diff --git a/Cargo.lock b/Cargo.lock
index 278c04db..31927dad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1228,7 +1228,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1237,7 +1237,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1258,7 +1258,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1272,7 +1272,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1288,7 +1288,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1300,7 +1300,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_fold"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "num-bigint",
  "oxide_bytecode",
@@ -1312,7 +1312,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1321,7 +1321,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1335,7 +1335,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1347,7 +1347,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1356,11 +1356,11 @@ dependencies = [
 
 [[package]]
 name = "oxide_net"
-version = "0.19.35"
+version = "0.19.36"
 
 [[package]]
 name = "oxide_parser"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1375,7 +1375,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1391,7 +1391,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1404,7 +1404,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1424,7 +1424,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1437,7 +1437,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.19.35"
+version = "0.19.36"
 dependencies = [
  "bumpalo",
  "chrono",
diff --git a/Cargo.toml b/Cargo.toml
index 677eafd7..de070c07 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,7 +25,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.19.35"
+version = "0.19.36"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"
diff --git a/crates/oxide_emit/src/class/field.rs b/crates/oxide_emit/src/class/field.rs
index c58e4bc0..dea4bded 100644
--- a/crates/oxide_emit/src/class/field.rs
+++ b/crates/oxide_emit/src/class/field.rs
@@ -14,10 +14,8 @@ impl Emitter {
         &self, elements: &[ClassElement], ctor_reg: u32, key_slots: &[Option<u8>], ctx: &mut CompileCtx,
     ) -> Result<(), String> {
         let saved_static_this = ctx.static_block_this_reg;
-        // static_block_this_reg 保留 u8（this 槽语义，254 特判），ctor_reg 超 u8 界时报错而非静默截断。
-        ctx.static_block_this_reg = Some(
-            u8::try_from(ctor_reg).map_err(|_| format!("class constructor register {ctor_reg} exceeds u8 limit"))?,
-        );
+        // ctor_reg 是 vreg 号（RegAlloc 期压缩到物理域），直接存 u32，不截断。
+        ctx.static_block_this_reg = Some(ctor_reg);
         for (element, &key_slot) in elements.iter().zip(key_slots) {
             match element {
                 ClassElement::PropertyDefinition(prop) => {
diff --git a/crates/oxide_emit/src/compile_ctx.rs b/crates/oxide_emit/src/compile_ctx.rs
index 6e79483e..cf5f3dc8 100644
--- a/crates/oxide_emit/src/compile_ctx.rs
+++ b/crates/oxide_emit/src/compile_ctx.rs
@@ -66,7 +66,9 @@ pub struct CompileCtx {
     /// 源码是否为 `source_escape` 产物（动态编译入口）：正则字面量源文本切片
     /// 的池键形态据此选择（见 [`Emitter::source_encoded`]）。
     pub(crate) source_encoded: bool,
-    pub(crate) static_block_this_reg: Option<u8>,
+    /// 静态块内 `this` 的构造器寄存器（vreg 号，无 u8 上限，RegAlloc 期压缩到物理域）。
+    /// None 表示非静态块上下文，`this` 走常规 this 槽。
+    pub(crate) static_block_this_reg: Option<u32>,
     pub(crate) field_buffer: Option<FieldBuffer>,
     /// 类构造器模块中 `@@field_keys` upvalue 下标（实例字段 computed key 数组）。
     /// 类定义期求值一次存入 cell，构造器经此 upvalue 读取。
diff --git a/crates/oxide_emit/src/expr/this.rs b/crates/oxide_emit/src/expr/this.rs
index 82e5af80..9b665ee8 100644
--- a/crates/oxide_emit/src/expr/this.rs
+++ b/crates/oxide_emit/src/expr/this.rs
@@ -8,8 +8,12 @@ use oxide_ir::operand::Operand;
 impl Emitter {
     pub(crate) fn emit_this_expression(&self, ctx: &mut CompileCtx) -> Result<u32, String> {
         let r = ctx.alloc_reg();
-        let src = ctx.static_block_this_reg.unwrap_or(254);
-        let src_op = if src == 254 { Operand::This } else { Operand::Reg(src as u32) };
+        // None 是常规 this 槽；Some(reg) 是类构造器 vreg（vreg 号可越过 254，
+        // 按寄存器处理，不与 this 槽特判混淆）。
+        let src_op = match ctx.static_block_this_reg {
+            None => Operand::This,
+            Some(reg) => Operand::Reg(reg),
+        };
         ctx.inst(Inst::new(OpCode::LOAD_VAR, Operand::Reg(r), src_op, Operand::None));
         Ok(r)
     }
diff --git a/crates/oxide_emit/tests/emit_ir_tests.rs b/crates/oxide_emit/tests/emit_ir_tests.rs
index 7d141431..47365402 100644
--- a/crates/oxide_emit/tests/emit_ir_tests.rs
+++ b/crates/oxide_emit/tests/emit_ir_tests.rs
@@ -576,3 +576,33 @@ fn private_field_read_captures_object() {
     let names: HashSet<&str> = inner.upvalue_captures.iter().map(|c| c.name.as_str()).collect();
     assert!(names.contains("self"), "私有字段读路径目标对象须入捕获集");
 }
+
+/// 面 21：顶层 vreg 号越过 255 后，类静态块 `this` 仍正确读类构造器 vreg——
+/// 构造器寄存器不截断、不与 this 槽（254）特判混淆。
+#[test]
+fn static_block_this_reads_ctor_vreg_beyond_u8() {
+    // 大量顶层 var 把 vreg 号推过 255，再声明含静态块的类。
+    let mut src = String::new();
+    for i in 0..300 {
+        src.push_str(&format!("var v{i} = {i};\n"));
+    }
+    src.push_str("class C { static { this.x = 1; } }");
+    // 修复前此源码 emit 报「class constructor register … exceeds u8 limit」，
+    // `emit_ir` 会 panic。
+    let ir = emit_ir(&src);
+    // 静态块 `this` 应发 LOAD_VAR 读构造器 vreg（Operand::Reg），非 this 槽。
+    let this_load = ir
+        .insts
+        .iter()
+        .filter(|i| i.op == OpCode::LOAD_VAR)
+        .find(|i| matches!(i.a, Operand::Reg(_)))
+        .expect("静态块 this 应发 LOAD_VAR Reg");
+    let Operand::Reg(r) = this_load.a else {
+        unreachable!()
+    };
+    assert!(r > 255, "静态块 this 的构造器 vreg 号应越过 255：{r}");
+    assert!(
+        !ir.insts.iter().any(|i| i.op == OpCode::LOAD_VAR && matches!(i.a, Operand::This)),
+        "静态块 this 不应走 this 槽"
+    );
+}