The invention relates to the field of coke tank overhauling and provides a coke tank jacking and bottom valve overhauling method for a carrier loader. The method comprises the following steps that three or more synchronous jacking oil cylinders are placed between the carrier loader and a girder at the bottom of a coke tank; the synchronous jacking oil cylinders are evenly distributed on the periphery of a coke tank bottom valve; all the synchronous jacking oil cylinders are started simultaneously to jack the coke tank to a set height; an operator goes into the coke tank to conduct overhauling; after overhauling is completed, a hydraulic system is controlled to enable push rods of the jacking oil cylinders to descend, and the coke tank descends along with the push rods until two bottom valve doors of the coke tank are closed. The hydraulic system is utilized to jack up the coke tank to the specific height, cost is low, the automation degree is high, and the working efficiency is high. When the operator enters the coke tank to overhaul the bottom valve, even if an accident happens, for example the synchronous jacking oil cylinders lose efficacy or slip, and the coke tank inclines or falls back to the carrier loader, the operator will just be hurt without a life risk; compared with the method that the operator conducts overhauling below the coke tank, the safety risk is lowered.