The utility model discloses a double -deck motor mainpole coil jig for welding, it includes: inside casing alignment device, inside casing alignment device be used for the aliging inside casing of first layer coil and second floor coil to form a holistic motor mainpole coil, strutting arrangement, strutting arrangement is used for supporting and fixing a position the motor mainpole coil after aliging, nipple closing device, nipple closing device sets up on strutting arrangement, and nipple closing device is used for supporting the side of the nipple of the first layer coil on the strutting arrangement and the nipple of second floor coil by being in the same place. The utility model discloses not only can weld the nipple between the two -layer coil well, reduce moreover that copper is overheated to do benefit to the standard operation that brazes to insulating material harm, require lowly to operating personnel, product quality is stable.