Abstract: Using the finite element analysis software ABAQUS, a sequentially coupled fillet welding thermal-stress program was developed to calculate the stress distribution of plate sealing joint in the high pressure hydrogenation heat exchange. Based on the numerical solutions and the orthogonal method, the influence of four welding parameters including welding current, welding voltage, welding speed and preheating temperature on residual stress distribution was analyzed and a group of optimal welding parameters were obtained, which provided a reference for preventing the failure of fillet weld sealing joint in the high pressure hydrogenation heat exchange.