The invention relates to an automotive transmission, comprising a box body, a rear cover, a gear shift, a gear change mechanism and a main reducing gear, wherein the right side of the box body is connected with the rear cover through bolts, the gear change mechanism is arranged at the upper part of the box body, the gear shift is connected with the lower part of the gear change mechanism, the main reducing gear is arranged at the lower part of the box body, the transmission is internally provided with an input shaft, an output shaft and assemblies thereof in parallel, the main reducing gear is internally provided with a main reducing gear carrier, a differential transmission gear carrier, an output main reducing gear and assemblies thereof, and the gear change mechanism is matched with the main reducing gear through the input (output) main reducing gears. The invention integrates integrated design of gear shift, differential speed and deceleration, has compact structure, realizes all-time four-wheel drive, has good tightness of each contact surface of assembly, bolts, oil seal, housing and the like, avoids oil penetration and leakage greatly, saves energy, has easier and more flexible operation, improves the power transmission efficiency and enhances the gear shift performance.