The invention discloses a lifting device for a spare tire of an engineering dump truck. The lifting device structurally comprises a mounting bottom plate, fixed blocking boards, a central shaft rod, achain retracting reel, a worm gear, a force-receiving transmission rod, a sealing ring, an anti-jamming mechanism and a power worm, wherein the two fixed blocking boards are separately arranged on the left side and the right side of the upper surface of the mounting bottom plate; the fixed blocking boards are connected to the mounting bottom plate by electric welding; circular holes of which thediameter is the same as the diameter of the central shaft rod are formed in the middle of the fixed blocking boards; the chain retracting reel is mounted between the fixed blocking boards through thecentral shaft rod; the worm gear is arranged on the right side surface of the central shaft rod and positioned on the right of the fixed blocking boards; and the worm gear is connected to the centralshaft rod by electric welding. By virtue of the anti-jamming mechanism, when the spare tire needs to be removed, the lifting device can stir up and clear silt in the engineering dump truck through a first stirring structure and a second stirring structure so as to reduce damage to parts when the spare tire is wound down; and at the same time, a rotating structure is utilized to effectively reducestrength required by a user to wind down the spare tire.