Abstract: According to the disadvantages of dynamic description logic actions theory at describing and analyzing multi-action relationships, especially concurrent relationship, a method to model and analyze dynamic description logic actions relationships with Petri nets is presented. Firstly, a dynamic description logic action can be equally modeled with its Petri nets, and then, multi-actions will have their Petri nets model through logical reasoning on actions description and sharing synthesis operation of Petri nets. Based on their Petri nets model, the relationships about multi-actions can be analyzed and determined by correlative analysis methods of Petri nets, such as reachable graph. This method not only effectively unites dynamic description logic and Petri nets theory but also extends the modeling and analysis abilities of dynamic description logic actions theory.