Abstract: The 20 vehicles were post-processed and modified according to the group to test the improvement of particulate and gaseous pollutants before and after the transformation.By measuring the data of the test equipment Nanomet 3 and Testo 350 before and after the post-treatment equipment,the filtration efficiency of the particulate pollutants and the discharge concentration ratio of the gaseous pollutants were analyzed before and after comparison.The results show that the average particulate number(PN)filtration efficiency of the four test vehicles have reached more than 95%,the maximum reaches 99.1%;while the average PN filtration efficiency on the chassis dynamometer is 95.2%,the highest is 98.3%.The diesel engine is equipped with two sets of DPF and DOC vehicles.The CO was reduced by 86.7% and 85.9% compared with the CO concentration before the reform.The diesel engine was only equipped with two sets of DPF vehicles,and the CO increased by 3% and 5% compared with the CO emission concentration before the transformation.For NOX,the ratio of the concentration before and after the transformation approached 1,and basically no change,but some of the forms were transformed,and NO2 fell to 43.7% before the transformation.