Abstract: This paper presents a simplification method of Petri net based on knowledge reduction.With the method of attribute-oriented reduction，it removes the redundancy rules and conditions of production rules corresponding to Petri net，and then simplifies the rules to the key rules.The paper also transforms the simplified production rules into Petri net model in which the number of nodes is reduced and the net system is simplified in certain degree.The simplified model contains the same information as before，but the numbers of place and transition are reduced.The reasoning process based on the model becomes easier and more efficient.Using a disease case to test the method at the last，the results show that this method is simple and practical，the complexity of time and space is efficiently reduced far and away，and the efficiency of searching and reasoning is improved.

摘要： 提出一种基于知识约简的Petri网模型简化方法，利用知识约简中的属性约简方法，去除Petri网对应的产生式规则的冗余规则和冗余条件，简化产生式规则得出关键规则。经过知识约简后的规则库转化为Petri网模型，此时的Petri网模型的结点数目减少，因此在一定程度上降低了网系统的复杂程度。简化后的模型保持原有的信息量，而所含的库所、变迁得到了减少，在其基础上进行的知识推理，更加简单和高效。最后通过一个病例实例说明，此方法简单实用，可以有效减少时间和空间复杂度，提高知识搜索和推理效率。