A welding fixture comprises a suction assembly, a drive assembly, and a positioning assembly. The suction assembly comprises a fixing member and a suction member slidably coupled to the fixing member. The drive assembly couples the fixing member to the suction member. The suction assembly comprises a positioning member slidably coupled to the fixing member, a flange protruding from the positioning member, and an elastic member sleeved on the positioning member. The elastic member is configured to bias the flange away from a side of the fixing member. The drive assembly can move the suction member and thereby moving the workpiece towards the positioning member, so that the weldment makes contact with the workpiece via the positioning member.