SDH设备是SDH网的重要组成部分,对保证SDH网的正常运行起着至关重要的作用。文中首先介绍了SDH设备故障特点,随后分析了基本Petri网描述和分析SDH设备故障诊断问题时存在的局限性,给出了适合于SDH设备故障诊断的故障诊断方法。最后利用一个实例验证了该方法的正确性、简单性和有效性。结果表明该方法是一种有效的SDH设备故障诊断方法。 SDH equipment is an important part of the SDH network, and plays an important role in ensuring the normal operation of the SDH network. The paper first introduces the characteristics of SDH equipment failure, and then analyzes the limitations of the basic Petri nets when describing and analyzing SDH equipment fault diagnosis, and presents a fault diagnosis method suitable for SDH equipment fault diagnosis. Finally, an example is used to verify the correctness, simplicity and validity of the method. The results show that this method is an effective method for fault diagnosis of SDH equipment.