In order to solve the problem of excessive ventilation scale caused by the high value of vehicle pollutant standard emission in highway tunnel ventilation calculation, according to the investigation and statistical analysis of vehicle emission in China, this paper reveals that the annual average decline rate of carbon monoxide and CO emission of mainstream fuel vehicles in the past 10 years is between 5.8% ~ 9.8%, and the annual average decline rate of smoke Ⅵ emission is between 6.9% ~ 10.1%. In 2020, vehicles with national Ⅲ and above emission standards were dominant, with carbon monoxide CO and soot Ⅵ emissions accounting for more than 85% and 97% respectively. The benchmark emissions of carbon monoxide CO and soot Ⅵ in national Ⅲ standards are 41% and 18% calculated in Guidlines, respectively. Based on the comprehensive analysis of the national industrial plan for the development of new energy vehicles and the carbon peak action plan before 2030, it is proposed that the calculated air demand of vehicle pollutants diluted by highway tunnel ventilation will reach the peak in 2030, the value of the benchmark emission of pollutants calculated by ventilation shall be taken according to the national Ⅲ standard, and the benchmark emissions of carbon monoxide CO and smoke Ⅵ shall be 50% and 34% respectively calculated in Guidlines. The reference emission value is economical, reasonable and relatively safe. For the super long highway tunnel, half the scale of ventilation shaft can be saved. The research results not only provide reference for the ventilation design and calculation of highway tunnel, but also provide technical support for the revision of ventilation calculation code and highway tunnel ventilation control.