Petri net overcomes the disadvantage of dynamic description logic actions theory at describing and analyzing multi-action relationships, especially about concurrent relationship. The method to automatic get the Petri net model of dynamic description logic actions is presented. At first, getting Petri net incidence matrix of each action from its dynamic description logic description, and then, using description logic reasoning technology to find the equivalent condition descriptions of actions, executing sharing synthesis operation with their Petri nets incidence matrixes of actions and getting the Petri net model of dynamic description logic actions.