The invention mainly relates to a folding bicycle which comprises a frame, a directing system, a driving system and a braking system. The frame comprises a front fork vertical tube, a front frame tube, a rear frame tube, a rear frame connecting rod, a rear fork, a saddle, a saddle tube, a seat tube bundle, a seat tube and the like. The folding bicycle is characterized in that the upper end of the front fork vertical tube is hinged to the front end of the front frame tube, and the rear end of the front frame tube is movably connected with the lower end of the seat tube; the rear frame connecting rod is movably connected with the lower end of the seat tube and fixedly connected with the rear frame tube, and the rear frame tube is fixedly connected with the rear fork; the lower end of the front fork vertical tube is hinged to the front end of a front fork vertical tube support rod, the rear end of the front fork vertical tube support rod is movably connected with front end of a seat tube support rod, the seat tube support rod is movably connected with the front frame tube through a support rod shaft, the rear end of the seat tube support rod is hinged to a seat tube support rod sliding sleeve, and the seat tube is sleeved with the seat tube support rod sliding sleeve. According to the folding bicycle, the structure is compact, the used materials are few, and the whole bicycle weight is small; by adopting the multi-portion folding design, the bicycle is smaller after being folded, therefore, the bicycle can be put in a traveling bag, and carrying is convenient.