A chassis welding device for welding brackets as standard members to a body of a chassis includes a frame, a first transferring member, a plurality of loading mechanisms, a plurality of carriers, a conveying member, a shifting member, and a spot welder. The loading mechanism transfers standard members to individual preset positions on the carrier to face the solder joints on the standard members away from the carrier. The first transferring member transports the carrier to the shifting member. The shifting member transfers the carrier from the first transferring member to the spot welder. The conveying member transfers the body into contact with the solder joints. The spot welder applies heat to melt the solder joints to bond the standard members to the body.