The invention provides a transmission of a road roller. The transmission comprises a reversing synchronizer arranged, a speed variable synchronizer, an input shaft, an output shaft, an intermediate shaft, a short cylindrical bearing, a tapered roller bearing, a needle roller bearing, a reverse idler gear, a reverse idler gear shaft, a reversing gear set, a speed variable gear set composed of paired gears with different transmission ratios, and an output flange, wherein the speed variable synchronizer, the input shaft, the output shaft, the intermediate shaft, the short cylindrical bearing, the tapered roller bearing, the needle roller bearing, the reverse idler gear, the reverse idler gear shaft, the reversing gear set, the speed variable gear set composed of the paired gears with the different transmission ratios, and the output flange are arranged in a shell. According to the transmission of the road roller, the manipulation of the change of the forward gear position and the reverse gear position is easy, operation is clear, and gear shifting is easy and convenient; the number of the gears of the transmission of the road roller is increased compared with a transmission of a traditional structure, three forward gears are provided, and three reverse gears are provided; gears can be increased and extended conveniently, the structure is more compact, the number of the parts is less than that of parts of the transmission of the traditional structure, and the cost is further lowered; interchangeability is good, the size and the installing method of the transmission of the road roller are completely the same as those of the transmission of the traditional structure, and upgrading and updating of the transmission with the low cost are facilitated.