For Mg car and Fiat car of our company, the application research of key technology of CVT electro-hydraulic control system was carried out, including matching rules of CVT car, integrated design of electronic control module and development of engineering software, reliability and electromagnetic compatibility research of electronic control module, integration of CVT prototype, bench performance test of CVT prototype, vehicle matching and muffler exhaust pipe performance And adaptability test. The prototype has been completed, and key technologies and patents with independent intellectual property rights have been obtained and ready for industrialization. After the completion of the project, the following main technical indicators are planned to be obtained: (1) fuel economy: about 8 ~ 10% higher than that of the same type of vehicle equipped with at; (2) power performance: 5 ~ 8% higher than that of the same type of vehicle equipped with at; (3) harmful gas emission is reduced by about 10% according to urban cycle test; (4) self diagnosis function with CAN bus interface is adopted. According to the prediction of relevant departments, China's automobile production will reach 5 million in 2010. If the CVT is calculated according to 10% loading rate, at least 500000 sets are required per year. Therefore, the future CVT muffler structure project has a very broad market prospect. The technology will be used in Marquis, Fiat or other vehicles.