A device for resistance spot welding, comprising a pair of electrodes located on a same welding surface of a to-be-welded assembly, the to-be-welded assembly has a symmetry axis , the pair of electrodes are symmetrically arranged on two sides of the symmetry axis , an end of each electrode is provided with a special-shaped contact surface , and each special-shaped contact surface is shifted in a direction away from the symmetry axis relative to an electrode axis ; wherein the electrode includes an electrode tip and an electrode rod , an end of the electrode tip is detachably sleeved on an end of the electrode rod , another end of the electrode tip is provided with a boss, and an end surface of the boss is provided with the special-shaped contact surface ; characterized in that : the special-shaped contact surface is used for shifting a current density centerline generated by the pair of electrodes in a direction away from the symmetry axis relative to the electrode axis , and/or for deflecting a current density of each electrode in a direction away from the welding surface within the to-be-welded assembly; the special-shaped contact surface comprises a first contact surface , and a second contact surface , wherein a geometric center of the first contact surface is located on a side of the electrode axis distal to the symmetry axis , the second contact surface is connected to a side of the first contact surface proximal to the symmetry axis , and an area of the first contact surface is larger than an area of the second contact surface . the to-be-welded assembly has a symmetry axis , the pair of electrodes are symmetrically arranged on two sides of the symmetry axis , an end of each electrode is provided with a special-shaped contact surface , and each special-shaped contact surface is shifted in a direction away from the symmetry axis relative to an electrode axis ; wherein the electrode includes an electrode tip and an electrode rod , an end of the electrode tip is detachably sleeved on an end of the electrode rod , another end of the electrode tip is provided with a boss, and an end surface of the boss is provided with the special-shaped contact surface ; characterized in that : the special-shaped contact surface is used for shifting a current density centerline generated by the pair of electrodes in a direction away from the symmetry axis relative to the electrode axis , and/or for deflecting a current density of each electrode in a direction away from the welding surface within the to-be-welded assembly; the special-shaped contact surface comprises a first contact surface , and a second contact surface , wherein a geometric center of the first contact surface is located on a side of the electrode axis distal to the symmetry axis , the second contact surface is connected to a side of the first contact surface proximal to the symmetry axis , and an area of the first contact surface is larger than an area of the second contact surface . the special-shaped contact surface is used for shifting a current density centerline generated by the pair of electrodes in a direction away from the symmetry axis relative to the electrode axis , and/or for deflecting a current density of each electrode in a direction away from the welding surface within the to-be-welded assembly; the special-shaped contact surface comprises a first contact surface , and a second contact surface , wherein a geometric center of the first contact surface is located on a side of the electrode axis distal to the symmetry axis , the second contact surface is connected to a side of the first contact surface proximal to the symmetry axis , and an area of the first contact surface is larger than an area of the second contact surface . <EOS>