Abstract: Affected by the wet and high-salt environment on the seashore,qualified rate of austenitic stainless steel welded joints was low. In order to solve the technical problem,welding process tests of ultra-fine grain austenitic heat-resistant stainless steel were carried out in the paper. welding parameters were optimized to prevent defects such as porosity,cracks and root fusion in the weld,and finally a complete set of welding process of austenitic heat-resistant stainless steel in humid and high-salt areas was developed.