从概念的角度分析了活动图并非结构的不足，系统地研究了时序模糊状态下的语音描述，以工作流的循环模式鉴别器作为实例，提出了活动图与形式化规范相结合的解决方法。最后结合抽象状态自动机ASM作为语义补充构造了鉴别器的活动图模型，从分支、合并、事件捕获等方面定义了详尽的规则，提高了模型的正确性、可验证性和一致性。-The insufficient of concurrent structure of activity diagram is analyzed in concept level,and the semantic of undefined scheduling is researched,and then by the case of loop discriminator,combines the activity diagram with formal specification.In the end,the discriminator model of activity diagrm is given with ASM semantics,rule is defined in Fork.Join and event capturing ect.,the correctness,verifiability and consistency are improved.