A method of entirely replacing a coking furnace riser tube of a whole furnace comprises the following steps of: closing a riser tube coal gas turnover plate, removing a riser tube cover and a coaling hole furnace cover, putting a small chimney on an opened coaling port, extending two compressed air tubes into a coking hole, pressing a flame originally coming from the riser tube in a carbonization chamber back into the carbonization chamber to go out from the small chimney, covering the riser tube, lifting a vertical tube of the riser tube, pulling out the compressed air tubes from the coking hole, putting a fire retardant cover in a riser tube base hole of the carbonization chamber, replacing a base, taking out the fire retardant cover, dismounting the old riser tube, fixing a new riser tube, hoisting a bridge tube in place and mounting a riser tube water seal tube and a riser tube connecting rod in place. According to the method, the replacement of the riser tube in the whole furnace can be achieved under the condition that the coking furnace is not subjected to coke pushing; damages of furnace wall bricks of the carbonization chamber and leakage due to the replacement of the riser tube in the empty furnace after the coke pushing are avoided; and a furnace wall of the carbonization chamber is not required to be subjected to air pressure sealing and ceramic welding repair.