On the 2020 IEEE 23rd International Conference on Intelligent Transportation Systems (ITSC), P. Gao et al^[1] published the research on the safety function of the ATP system (a control system of the communication-based train control system), they proposed a new analysis method for the ATP system, the Dynamic Fault Tree analysis method. The Dynamic Fault Tree is a system of methods for evaluating the reliability and safety of a complex system, it is also a kind of deductive method, which is based on the fault event and is analyzed step by step according to the top-down sequence through certain logical reasoning steps until the result is reached. The Dynamic Fault Tree analysis method is devoted to modeling the fault logic according to the dynamic fault behavior, and conforms to the functional design of signal system. It is worth mentioning that logical analysis based on the Dynamic Fault Tree analysis method method often analyzes the emergence of problems at the same time, instead of analyzing it layer by layer, it can greatly improve the efficiency of problem solving.

The order of problem solving based on the Dynamic Fault Tree analysis method is: 1. Identify the possible fault events. 2. According to the possible fault events, establish the analysis process of them. 3. Through the control system(just like the ATP control system), analyze whether the fault events occur. 4. If the fault events occur, solve them through the control system(just like the ATP control system).