The one-piece trolley folding structure comprises front legs, rear legs, a first rotating shaft, a second rotating shaft, a rotating shaft seat and a fixing piece, the front legs are installed on the two sides of the first rotating shaft, the second rotating shaft is sleeved on the first rotating shaft and fixedly connected with the rear legs, the rotating shaft seat is installed in the middle of the upper side of the first rotating shaft, and the fixing piece is installed on the rotating shaft seat. Connecting rods are arranged at the two ends of the rotating shaft seat, one end of each connecting rod is inserted into the corresponding fixing hole of the second rotating shaft, the other end of each connecting rod is inserted into the rotating shaft seat, and a fixing piece is installed on one side of the rotating shaft seat; compared with the prior art, an original folding structure is improved, the improved folding structure is smaller and more exquisite, when the folding structure needs to be used, only the fixing piece needs to be pulled out, the positions of the fixing piece and the first rotating shaft need to be changed, the folding structure is simple and convenient, errors cannot occur, and dangerous accidents are avoided.