This research uses the gate type double wire submerged arc welding machine,welding wire diameter of 4.8 mm,fillet welding in the flat position,the welding process test of h-shaped steel body with a web thickness of 20 mm is carried out. The analysis of test results,and with the help of the mathematical model of the T joint,reasonably adjust welding angle,wire eccentric distance and the interrelation between the position of weld fusion zone,and set the welding angle and wire position according to the mathematical model,the web thickness of 20 mm of H-shaped steel,in the case of none groove,H-shaped steel combination of weld has reached the requirements of full penetration welds,UT inspection qualified. The mechanical properties of the specimens are sampled,the impact performance and hardness of the welded joints are in accordance with the requirements of the relevant specifications,and the metallographic structure is well formed from macroscopic and microscopic metallographic analysis.