Abstract: In order to investigate the effects of subsea gas pipeline leakage on its adjacent offshore platform, KFX, a 3D CFD software, was used to simulate the process and consequence of a fire which was initiated when the gas leaked out from the pipeline reached the sea surface. In the simulation, the transient leakage rate was taken as the input parameter, and such factors as relative position of the gas release surface to the platform, wind direction and wind velocity were considered. In case that cracking leakage happens on the subsea pipeline at depth of 189 m, the platform will be greatly influenced by the fire if the release surface of the leaked gas is below the platform. In this situation, the safety facilities are vulnerable to be impaired, the platform crew can hardly evacuate, and the probability of accident escalation is high. The maximum horizontal influence distances of the fire at various wind velocities were calculated for the situation that the gas release surface was far from the platform. Based on the analysis results, some recommendations on risk management and emergency preparedness were proposed for the events of subsea pipeline leakage in terms of accident confirmation, alarm, rescue, evacuation and safety design.