The cost of the auto parts manufacturing industry is subject to the upstream industry and its own management level, while the parts required by downstream auto manufacturers mainly come from fixed suppliers. The largest buyers of auto parts are auto parts dealers, which are also the main channels for auto parts sales. The profit margin depends on the industry status, competitive structure and bargaining power of parts companies with downstream industries. In the relatively mature international automobile market, 50%-60% of profits are generated in the service sector. China has experienced tremendous economic development in the first ten years of the 21st century, and the automobile industry has benefited accordingly. Afterwards, a huge "automotive aftermarket" is entering a period of rapid growth, and the auto parts industry has a bright future.