The invention provides a lifting appliance mechanism and an adjustment system therefor. The lifting appliance mechanism includes a support assembly, a support lifting assembly and two adjustment assemblies. The support assembly is slidingly arranged on a rail so that the lifting appliance can move on the rail. The support lifting assembly includes a jib, a corbel, and a support block, wherein oneend of the jib is rotatably connected to the support assembly, the corbel is arranged on the other end of the jib to support a to-be-lifted driving cab; a support rod is arranged on the lower end of the jib horizontally, wherein the central line of the support rod is in parallel with a rotational central line of the jib; the support block is slidingly arranged on the support rod; two adjustment assemblies are disposed at two sides of the rail so that when the lifting appliance moves to between the adjustment assemblies, the adjustment assemblies drive the support block to move to a preset position along the support rod. The mechanism can adapt deriving cabs in different models and has good universality.