Abstract: In order to study the influence of gear on CO₂ emission, pollutant emission and dynamic parameters, the 7-gear dry dual clutch transmission vehicle was selected as the test vehicle to carry out 4 RDE tests on the same road. The data were basically divided according to gear. The results show that CO₂, CO, PN (without GPF) emission factors have significant linear correlation with transmission ratio and RPA, while NO_x emission factors have slightly weak correlation with transmission ratio and RPA; The emission characteristics of CO2 at different gears and vehicle speeds can be explained by the emission analysis method based on the emission of a single working cycle of the engine with the transmission ratio as a variable. This method can also explain the emission characteristics of other pollutants. In the calibration of the whole vehicle aiming at reducing carbon emission and pollutant emission, the influence characteristics of transmission ratio and emission can be used as a reference for calibrating the shift control strategy. Increase the service time of low gear, RPA tends to increase, V·a_pos_[95] tends to decrease, which can improve the chances of passing the dynamics test.