The invention provides a transmission mechanism for an S spring roll bending machine, belongs to the technical field of machinery, and solves the problem that the transmission of a roll bending machine is unstable in the prior art. According to the transmission mechanism for the S spring roll bending machine, the S spring roll bending machine comprises a base and a vertical plate vertically fixed on the base, and a rotating shaft I, a rotating shaft II, a rotating shaft III and a rotating shaft IV are arranged on the vertical plate. The transmission mechanism is arranged on one side of the vertical plate, and comprises a driving motor fixed on the base; the output shaft of the driving motor is horizontally arranged, and an output gear I is arranged at the end part of the output shaft; a driving shaft is rotationally arranged on the base through a bearing and a bearing seat, an output gear II is fixed at one end of the driving shaft, and the output gear I and the output gear II are connected through a chain I; and a clutch structure for enabling the output gear I not to rotate when the output shaft rotates is arranged on the output shaft. The transmission mechanism has the advantage of stable transmission.