The invention relates to the field of auxiliary devices of coal hot air furnaces, in particular to an automatic coal cinder crushing and ash removing device for a coal hot air furnace. The automatic coal cinder crushing and ash removing device comprises a furnace body. A plurality of coal cinder crushing claw groups are arranged in the furnace body through a bearing, the coal cinder crushing clawgroups are coaxially connected to a driving mechanism located on the outer wall of the furnace body, guide plates are symmetrically arranged on two side walls of the furnace body below the coal cindercrushing claw groups, two relatively moving grinder rolls are arranged below the guide plates, the grinder rolls are connected to the driving mechanism through grinder roll shafts, a plurality of splitter plates are arranged below the grinding rolls, and a collecting box located in the bottom of the furnace body is arranged below the splitter plates. The automatic coal cinder crushing and ash removing device solves the problem that health hazards on human bodies of operators and the environmental pollution are caused when coal cinder is cleaned and crushed manually in the prior art. By arranging a driving source, coordination of two movements is achieved without pre-debugging, so that the operation efficiency is improved. In addition, the whole driving mechanism is arranged on the outer wall of a hot blast heater body, so that the automatic coal cinder crushing and ash removing device is convenient to maintain and repair.