Abstract: The purification effect of selective catalyst reduction (SCR), exhaust gas recirculation (EGR), diesel particulate filter (DPF) and diesel oxidation catalyst (DOC) on nitrogen oxide (NO_x) and smoke of diesel vehicles was studied by short cycle lugdown. It was performed lugdown emission test of NO_x and smoke opacity for 116 heavy-duty diesel trucks in line with China V and China VI emission standards, equipped with the above exhaust purification technologies. It was compared the emission data of vehicles, the purification effect of the purification technology evaluated, the difference of emissionsbetween100%VelHPMax and 80%VelHPMax test condition analyzed. It is found that the purification effect of EGR and SCR integrated technology on NO_x is obviously better than single technology SCR or EGR, and the SCR is better than EGR. For vehicles equipped with EGR and SCR integrated technology and single technology SCR, the NO_x volume concentration is higher at 100% VelHPMax than 80% VelHPMax, while with single technology EGR is opposite. The smoke opacity value of diesel vehicles equipped with DOC and DPF integrated technology is significantly lower than single technology DOC. The smoke optical absorption coefficient of diesel vehicles inspected is higher at 100% VelHPMax than 80% VelHPMax. The results show that lugdown cycle test can distinguish effective the difference of purification effect of emission purification technologies of diesel vehicles.