The invention discloses an electric resistance welding gun with adapting blocks. The electric resistance welding gun comprises an installing plate, a water distributor and the two adapting blocks, wherein the installing plate, the water distributor and the two adapting blocks are arranged on a welding gun body, the water distributor is arranged on the installing plate through the adapting blocks,one ends of the adapting blocks are connected with the installing plate, the other ends of the adapting blocks are connected with the water distributor, and the adapting blocks are positioned betweenthe water distributor and the installing plate. The adapting blocks are arranged, one ends of the adapting blocks are connected with the installing plate, the connecting points are marked as A, the other ends of the adapting blocks are connected with the water distributor, the connecting points are marked as B, the angles between the connecting lines between the A and the B and the water distributor are adjusted, namely, the adapting blocks are rotated around the A to enable the other connecting point B to correspond to installing holes in the installing plate so that the requirement that thewater distributor with the same specification can be applied to the electric resistance welding guns with different types is met, the applicability is high, and the production cost is reduced.