Reducing tariffs is not only a way for countries to promote international trade, but also an important way to reduce the tax burden of taxpayers. For enterprises that buy imported auto parts, the most direct performance is price reduction. When the import tariff of domestic joint venture automobile manufacturers is reduced, the price of imported parts will be reduced, but the tariff of most automobile parts will only be reduced by 2%, which has little effect on the product price. There is a little room for price reduction. Compared with imported cars, there is about 10% room for price reduction, and the price reduction of domestic joint venture cars will be very small. Due to the Sino-US trade war, it is estimated that the tariff on imported cars originating in the United States will increase by 25% from July 6, and the price of imported cars in the United States will rise sharply.