Support replacing method

The invention discloses a support replacing method. The method involves a bridge, an original support, original support cushion stone, a first jack, a cutting wire, a second jack, a spiral cushion block, new support cushion stone and a new support. The support replacing method is reasonable and simple in structure, low in production cost, convenient to mount and complete in function; and accordingto the method, it can be effectively avoided that the elevation of the upper bridge changes to cause damage of auxiliary building, facilities and the like of the bridge. The support replacing methodrefers to static support replacing, the front-back state of the bridge is not influenced, and bridge posture changes cannot be generated. According to the support replacing method, a hydraulic pump station achieving synchronous control through computer operation is adopted as a control system, and therefore the need for definite-value pressurizing of the jacks at different positions is met, and itis ensured that step-by-st