Abstract: In order to conduct underwater welding of nuclear fuel pool, a set of local dry underwater welding equipment was developed. A test platform was built, and the underwater non-molten inert gas arc welding test was carried out in an acrylic tank by the device.The defective position on the stainless steel wall was repaired by using a circular patch.The results show that the welding seam is well formed after welding.It can realize the repairing of the underwater waste pool, and verify the feasibility of the local dry underwater welding device.