Ultrasonic welding, tin spot welding, short-circuit breaker replacement, and U-shaped card connection are commonly used design methods for automotive wiring harnesses. The development trend of my country’s wire harness industry is ultrasonic welding, and ultrasonic welding is the best design method recognized by the international community. When pressure is applied to the metal surface, a large amount of friction is generated on the metal surface, which in turn promotes welding between the molecular layers. Due to its high efficiency and low energy consumption, ultrasonic welding is widely respected. But this design method welding equipment is expensive, and the maintenance cost is high. U-shaped card connection is a widely used contact method in our country. After the copper wire and the U-shaped terminal are squeezed, the friction between the copper wires can effectively connect the U-shaped terminal. The operation process of the U-shaped card connection is relatively easy, the conductive effect is good, and the material price is low, which saves the cost.