To solve the problem that multidimensional computing code needs huge computing resources when it simulates the lead-bismuth reactor for a long time, based on the self-developed one-dimensional CFD code, integrating the zero-dimensional point reactor dynamics model and the two-dimensional fuel rod heat transfer model, and carring out the multi-physical field coupling, we have developed a system safety analysis code for lead-bismuth pool reactor. The international benchmark for Accelerator Driven Sub-critical System (ADS) beams transient accident, which was published by OECD/NEA, was used to process the steady-state and transient validation, and to ensure the accuracy of the model. The verification results show that the code developed is in good agreement with the published results in terms of key parameters, and the computational resources required are obviously smaller than those of the multi-dimensional computing code. It is proved that this code can be used for preliminary thermo-hydraulic and safety analysis of lead-bismuth reactor.