Abstract: In order to ensure the quality of inside coolant in the internal cooling system, the fluid pipeline and tank of the liquid receiving part of the equipment were prefabricated and welded with 304 or 316 austenitic stainless steel. Based on the unique working conditions of valve cooling equipment and the characteristics of base material, influence of welding defects on the quality of inside coolant was summarized through theoretical analysis and equivalent simulation test. The corresponding strategies for welding defects of stainless steel pipeline in valve cooling equipment was put forward, which provided a reference for improving the operation reliability of valve cooling system.