The transmission delay of time sensitive networking is affected by many network factors, so it shows significant dynamic characteristics. In order to optimize the flow scheduling strategy and meet the communication requirements of time sensitive applications to the maximum extent, it is necessary to study the delay characteristics comprehensively by using effective simulation methods. Firstly, the working principle and delay influencing factors of time sensitive networking flow control mechanism are analyzed, and the basic goal of delay characteristic simulation research is defined; then, by comparing the technical characteristics of different network simulation methods, the MATLAB / Simulink simulation tool is selected, and the delay model and simulation algorithm are designed;finally, the feasibility and correctness of the simulation method are verified for the main application scenarios of flow control mechanism. The research results have reference value for time sensitive networking delay characteristics research and flow control strategy optimization design.