Basing on analysising the importance of maintenance support process modeling and simulating, we have analysised the application characteristics of Petri model used in the process simulation. Then, aiming to some equipment system maintenance support process, we established the corresponding TTPN model. At last, by simulation we analysised indexes such as the ratio of resource using and the ratio of task success at different maintenance support resource configuration, which offers decision support to the optimizing configuration of maintenance support resources. The results of simulations prove the practicability and feasibility of the method.