The utility model provides a booster for replacement of a flange type gate. The booster can be installed on the flange type gate and comprises a boosting device, the boosting device comprises a left baffle, a right baffle, a left bearing board, a right bearing board and a screw, one end of the left baffle is an insertion end capable of being inserted in the connection face of a left flange and a left pipeline flange, one end of the right baffle is an insertion end capable of being inserted in the connection face of a right flange and a right pipeline flange, one end of the left bearing board is provided with a left bearing ring arranged outside a pipeline in a sleeving mode, one end of the right bearing board is provided with a right bearing ring arranged outside the pipeline in a sleeving mode, the thread directions of the two ends of the screw are opposite, the left end of the screw is sequentially sleeved with a left clamping nut, the other end of the left baffle, a left thrust application nut and the other end of the left bearing board from right to left, and the right end of the screw is sequentially sleeved with a right clamping nut, the other end of the right baffle, a right thrust application nut and the other end of the right bearing board from left to right. The booster for replacement of the flange type gate can assist in smoothly detaching the flange type gate from the pipeline.