The present utility model relates to a special device for electric connector assembling. The device comprises a left clamping ring and a right clamping ring, a left operation handle and a right operation handle, and a left non-slip mat and a right non-slip mat, the left and right non-slip mats are glued and jointed on inner surfaces of the left and right clamping rings, the left and right clamping rings are respectively welded on jaws of the left and right operation handles, and the left and right operation handles are riveted through rivets. By adopting the device, problems that the welding zone and the crimping zone are damaged due to small electric connector butt joint assembling operation space, improper hand-operated plugging, bending and cracked pins and difficult disassembling can be solved, thus stability and reliability of the assembling quality of the electric connector can be enhanced, production efficiency can be enhanced, labor intensity and production costs can be reduced.