Taken the WHPB wellhead platform in Bozhong 13-1 gas field as an example, based on Flaresim and Fluent simulation software, the design, radiation and gas diffusion analysis of the Bozhong 13-1 WHPB cold vent system are analyzed by numerical simulation methods, and the performance of the cold vent pipe is mainly evaluated. Whether the length and cold vent head size meet the radiation and diffusion requirements and the impact of the cold vent system on the platform under emergency discharge is evaluated. According to the simulation research analysis and verification with drilling and completion professionals, the design of the platform cold vent system meets the requirements, and the study provides a reference for the design of offshore platform cold vent system.