Based on the theory of general Petri net, fault tree technique and theory of fuzzy set, a theory system of fuzzy Petri net suitable for fault diagnosis is established, which is used for an example of fault diagnosis for FMS. 基于一般Petri网理论、故障树技术和模糊集理论,建立了适用于故障诊断的模糊Petri网理论体系,并用于FMS的故障诊断实例中。