Abstract: The dynamic concurrency and fuzzy of the fuzzy Petri net can well describe the dynamic and spread process of the fault and the concurrency and fuzzy of the knowledge in knowledge database. Fuzzy Petri net was expanded to weight fuzzy Petri net, and particle swarm optimization was used to optimize the weight and threshold of the Petri net, this reduces the reliance on the expert’s experience and effectively improves the generalization ability of the fuzzy Petri net.