本文概述了Petri网的历史、发展、研究方法及应用领域，同时介绍了Petri网的基本原理，并给出了一个计算机网络链路层数据传输协议——停等协议的Petri网模型。最后，概述了Petri网研究和应用中出现的问题，展望了Petri网的发展方向。

-This article outlines the history of Petri nets, development, research methods and applications, and introduces the basic principles of Petri nets, and gives a computer network link layer data transfer protocol- Holding Petri net model of protocol. Finally, an overview of research and application of Petri net problems, prospects of development of the Petri net.