The diversified vertical integration strategy is to build a complete vehicle production capacity ranging from interiors, paints, to chassis and engines. BYD has 70% of its components produced on its own, which has caused a significant cost reduction. A newcomer in the automotive industry will inevitably have problems with low technology and poor product stability, and excessive investment has made BYD not have enough money to do all aspects of the car. After 2015, these problems were prominently reflected. As the domestic automobile market becomes more and more mature, consumers begin to pursue a higher quality of automobile products. Therefore, several models of BYD have begun to decline in sales due to more problems. In addition, while developing new energy vehicles, BYD has made a big foray into electric mine cars, electric sanitation vehicles, electric port vehicles, electric construction machinery, etc. In short, the biggest problem is excessive investment, which leads to no specialization, product quality is not up to Your own star product.