Intcgral-type shell of car-bridge for trailer is researched and produced by Henan Hongyang Axle Spindle Compay Through the whole hot extrusion, it can be formed by high quality low-alloy seamless steel pipe. The part is made by a whole pipe without welding process. Therefore, itcan avoid the potential danger with welding process. The streamline of its metal is smooth and reasona ble. By overall quenching and tempering, it has many advantages, such as good machine capability, light product weight, great bearing capacity, low natural price, which is the first choice product for the new generation good performance trailer bridge.