For wire harnesses with a cross-sectional area exceeding 50mm2, it is difficult for conventional ultrasonic metal welding equipment to achieve the ideal welding effect. When welding high-voltage wire harnesses, it is necessary to apply a large welding pressure. Since most of the conventional welding equipment is designed with a cantilever structure, the bending phenomenon of the actuator will occur, resulting in low welding energy conversion efficiency. In order to compensate for the loss of energy, the welding amplitude is usually increased. However, this not only fails to improve the problem, but also causes more serious problems. For example, a large amplitude will increase the internal core stress, and may damage the wire harness, so it is impossible to achieve Welding quality requirements required by automobile manufacturers.