Arch bridge double-suspender synchronous tensioning device and synchronous tensioning method and system

The invention discloses an arch bridge double-suspender synchronous tensioning device, a synchronous tensioning method and a synchronous tensioning system. The device comprises a supporting system, a loading system and a tensioning system, the loading system is arranged on a supporting platform in the supporting system and comprises a loading lever, a support rod and a loading device, and the tensioning system comprises a main tensioning rod, a hydraulic rod and a hoop; the rear end of the loading lever is rotatably connected with the upper end of the support rod, the support rod is fixed on the supporting platform, the front end of the loading lever is movably connected with the upper end of the main tension rod, the lower end of the main tension rod is provided with a pair of hydraulic rods with different telescopic directions, and the rod ends of the hydraulic rods are respectively provided with a hoop; the loading device is arranged on the supporting platform, located below the loading lever and used for