The utility model discloses a synchronous stretch system used for prefabricating beams through a pre-tensioning method. The synchronous stretch system comprises a synchronous controller, a synchronous sub-station, a pump station, a stretching cylinder, a draw bar, and a draw seat, wherein the synchronous controller is connected with the pump station through a control cable, and is connected with the synchronous sub-station through a field bus at the same time, the pump station is connected with the synchronous sub-station through an oil pipe, a pressure sensor and a displacement sensor are installed on the stretching cylinder, the synchronous sub-station is connected with the stretching cylinder, the stretching cylinder is connected with the draw bar, and the draw bar is installed on the draw seat. The synchronous controller in the utility model can realize two control standards, namely strength and displacement, to the stretching cylinder and can automatically record sensor values, so as to reduce quality problems of the prefabricated beams employing pre-tensioning method due to reading errors and recording errors.