The national six emission standard is the national six motor vehicle pollutant emission standard, which is an upgraded version of the national five standard, and requires that carbon monoxide emissions and total hydrocarbons must be reduced by more than 50% on the original basis. According to the six standards of planning the country, it will be divided into two stages: 6A and 6B. The first phase starts from July 2020 1, and the second phase starts from July 2023 1.