Abstract: The delay characteristics of frame preemption in time-sensitive networking are relatively complex, and it is difficult to analyze the randomness of frame preemption using a single standard probability density function. In order to analyze the random characteristics of frame preemption delay in time-sensitive networking, the working mode of frame preemption mechanism and the influencing factors of frame preemption delay were studied, and the analytical expressions of stage preemption delay of different preemption frame lengths were given. The hybrid probability model was used to model the random characteristics of frame preemption delay, and the method of producing each component and its weight in the hybrid probability model were given. The randomness of frame preemption delay and the influence of frame length and link occupancy on the component weight of the delay mixed probability model were analyzed by numerical simulation. The research results have reference value for the development and optimization design of frame preemption simulation model in time-sensitive networking.