The extended finite state machine (EFSM) is a formal description language of model constrution. According to the chemical process characteristics, EFSM models and data dependencies are improved, and the chemical process EFSM model is constructed including variables, states, transitions, conditions and actions between variables. The method of static and dynamic variables transitions and fault propagation path analysis is proposed. The simulation CSTR experimental results of the typical chemical process show the effectiveness and feasibility of the EFSM model description and analysis methods. New ideas and methods are provided for the fault propagation analysis in the industrial process.