As the most common means of transportation in China, automobiles have brought considerable challenges to China's infrastructure due to the year-by-year increase in automobile exports in recent years. Therefore, China's policies towards the automotive industry have been different at different times, requiring the use of fiscal policies to guide and support the development of the automotive industry. Vehicle purchase tax (VPT), as an important tax in the automobile sales environment, plays a key role in the development of the automobile industry. This paper uses a difference-in-difference (DID) model to assess the implementation effect of China's third VPT incentives, taking the total monthly sales of vehicles enjoying China's VPT incentives as an explanatory variable, dividing them into a control group and an experimental group according to whether or not they enjoy the incentives, and adding the two influencing factors of the industrial value-added and the CPI as control variables. The results of the study show that China's third VPT incentive policy has had the desired effect, and that passenger automobile sales have continued to grow, boosting automobile consumption and, in turn, China's economic growth.