The invention discloses a tray trolley multi-station conveying system. Stations are arranged sequentially on a same system platform according to the assembly process. Tray trolley reciprocating driving mechanisms are independently arranged between previous stations and next stations adjacent to the previous stations, and thus tray trolleys can not only forward go to the next stations from the previous stations in the system conveying direction but also can backward go to the previous stations from the next stations in the reverse system conveying direction to form a trolley reciprocating section. The tray trolleys are used for driving workpieces to go forward or go backward, so that equipment on the same station can be used in different working procedures of the assembly process and are recycled aiming at the different working procedures of the assembly process. The recycle rate of the same equipment among the different stations in an assembly line can be effectively increased, accordingly, the equipment utilization rate is increased, the length of the assembly line is shortened, and the work cycle is improved.