diff --git a/Doc/全量验证表.md b/Doc/全量验证表.md
index 739e5d9..3379440 100644
--- a/Doc/全量验证表.md
+++ b/Doc/全量验证表.md
@@ -27,6 +27,7 @@
 | 19_recursive_call | 负例 | 编译 | REJECTED ok | link error: recursive call |
 | 20_line1 | 正例 | 编译+执行 | ok | 真值表 4 行全对 |
 | 21_var_temp | 正例 | 编译+执行 | ok | VAR_TEMP 每周期重置（a=10107/10108/10109） |
+| 22_multi_instance | 正例 | 编译+执行 | ok | FB 共享体多实例隔离（a=102/204/306） |
 
 ## line1 真值表（回放：io.input 顺序 EmergencyStop, I0_0；I0_1=0 未绑定）
 
@@ -37,4 +38,4 @@
 | 1 | 0 | 0 | ok（急停生效） |
 | 0 | 1 | 1 | ok |
 
-**结论：21/21 用例符合期望，ctest 14/14，全部绿。**
+**结论：22/22 用例符合期望，ctest 14/14，全部绿。**
diff --git a/tests/cases/22_multi_instance/EXPECTED.md b/tests/cases/22_multi_instance/EXPECTED.md
new file mode 100644
index 0000000..f114d4a
--- /dev/null
+++ b/tests/cases/22_multi_instance/EXPECTED.md
@@ -0,0 +1,6 @@
+# 期望：编译通过；FB 共享体多实例隔离
+
+- Counter 编译为**单一共享函数**（fn 0），MAIN 两次 `CALL 0`（c1/c2 各一次，c2 两次调用）
+- 调用点 `LOADK r1` 装载**不同实例地址**（值区偏移），字段访问 `LOAD_PTR/STORE_PTR r1+off`
+- `count` 是实例字段：c1 每周期 +1、c2 每周期 +2，互不干扰
+- 全局 `a = c1.q * 100 + c2.q`：周期 1/2/3 = 102 / 204 / 306
diff --git a/tests/cases/22_multi_instance/globals.st b/tests/cases/22_multi_instance/globals.st
new file mode 100644
index 0000000..1b42e52
--- /dev/null
+++ b/tests/cases/22_multi_instance/globals.st
@@ -0,0 +1,4 @@
+(* globals.st *)
+VAR_GLOBAL
+    a : INT;
+END_VAR
diff --git a/tests/cases/22_multi_instance/main.st b/tests/cases/22_multi_instance/main.st
new file mode 100644
index 0000000..c1b2c76
--- /dev/null
+++ b/tests/cases/22_multi_instance/main.st
@@ -0,0 +1,27 @@
+(* main.st *)
+FUNCTION_BLOCK Counter
+VAR_INPUT
+    inc : BOOL;
+END_VAR
+VAR_OUTPUT
+    q : INT;
+END_VAR
+VAR
+    count : INT;
+END_VAR
+    IF inc THEN
+        count := count + 1;
+    END_IF
+    q := count;
+END_FUNCTION_BLOCK
+
+PROGRAM MAIN
+VAR
+    c1 : Counter;
+    c2 : Counter;
+END_VAR
+    c1(inc := TRUE);
+    c2(inc := TRUE);
+    c2(inc := TRUE);
+    a := c1.q * 100 + c2.q;
+END_PROGRAM
diff --git a/tests/cases/22_multi_instance/project.toml b/tests/cases/22_multi_instance/project.toml
new file mode 100644
index 0000000..b78828d
--- /dev/null
+++ b/tests/cases/22_multi_instance/project.toml
@@ -0,0 +1,11 @@
+[project]
+name = "case22"
+entry = "program MAIN"
+cycle_limit = 1000
+dt_ms = 10
+
+[files]
+st = ["globals.st", "main.st"]
+
+[gvl]
+file = "globals.st"
diff --git a/tests/src/cases_test.cpp b/tests/src/cases_test.cpp
index 2dd9956..40ab3dc 100644
--- a/tests/src/cases_test.cpp
+++ b/tests/src/cases_test.cpp
@@ -66,6 +66,7 @@ namespace {
         {"19_recursive_call", Outcome::CompileError, "recursive call"},
         {"20_line1", Outcome::Ok, ""},
         {"21_var_temp", Outcome::Ok, ""},
+        {"22_multi_instance", Outcome::Ok, ""},
     };
 
     bool run_case(const char* dir, Outcome want, const char* keyword) {
diff --git a/tests/src/compiler_test.cpp b/tests/src/compiler_test.cpp
index 337f51a..073c5ee 100644
--- a/tests/src/compiler_test.cpp
+++ b/tests/src/compiler_test.cpp
@@ -202,7 +202,7 @@ static bool test_all_cases() {
         }
         ++n;
     }
-    CHECK(n == 21);
+    CHECK(n == 22);
     return true;
 }
 
diff --git a/tests/src/vm_test.cpp b/tests/src/vm_test.cpp
index 019f9d4..b1dd07e 100644
--- a/tests/src/vm_test.cpp
+++ b/tests/src/vm_test.cpp
@@ -374,6 +374,15 @@ static bool test_cases_positive() {
     CHECK(m.run_cycle() == vm::Fault::None);
     CHECK(slot(m, 0) == 10109);
 
+    // 22 多实例共享体：Counter 单函数服务 c1/c2，a = 102/204/306
+    CHECK(make_machine("tests/cases/22_multi_instance", &m, &err));
+    m.run_cycle();
+    CHECK(slot(m, 0) == 102);
+    m.run_cycle();
+    CHECK(slot(m, 0) == 204);
+    CHECK(m.run_cycle() == vm::Fault::None);
+    CHECK(slot(m, 0) == 306);
+
     // 20 line1：I 组合 → Q0_0 真值表（槽 0=急停 1=I0_0 2=I0_1 3=Q0_0）
     CHECK(make_machine("tests/cases/20_line1", &m, &err));
     struct {