Abstract: In order to study the welding process suitable for gas shielded welding of thin plate full-penetration butt joint in shipyard, the test of full-penetration butt welding of 5mm thick AH36 marine steel plate was carried out by using three welding methods: gas shielded welding with 1.0mm fluid-core wire, gas shielded welding with 1.0mm metal powder-core wire, and gas shielded welding with 0.8mm solid wire. The weld appearance, welding deformation and mechanical properties obtained by different welding methods were compared and analyzed, and the best way of gas shielded welding procedure of thin plates was finally obtained, providing practical experience for gas shielded welding of thin plates in the shipyard.