The invention belongs to the technical field of vehicle transmission and particularly relates to an automatic six-gear planetary transmission. The automatic six-gear planetary transmission achieves the purposes of being wider in transmission ratio range and excellent in performance and meeting the using requirements of wheeled vehicles. The automatic six-gear planetary transmission comprises planetary gear sets, an input component, an output component, four transmission components, three brakes and two clutches, wherein the input component and the output component are installed at the two ends and connected with an input shaft and an output shaft respectively. Thus, the automatic six-gear planetary transmission achieves six forward gears, and the transmission ratio range can reach 7.4. The three planetary gear sets are all simple single-planet planetary gear sets, the k value of each planetary gear set ranges from 1.7 to 3.7, and therefore the compact structure design can be achieved conveniently, and the size and the weight of a gearbox are reduced.