The invention provides an automatic deashing garbage incineration device, and solves the technical problem of automatic deashing of a fire grate of an incineration furnace. The automatic deashing garbage incineration device comprises a furnace body, a fire grate device, an air supply device and an oil supply device; the fire grate device is arranged in the furnace body, and comprises a fire grate module and a jacking module; the fire grate module is positioned in a combustion area; the jacking module is positioned between the combustion area and an ash storage area; the jacking module drives the fire grate module to vertically move up and down in a chute to clean soot accumulated on the fire grate module; and under a cooperating effect of a first cleaning groove module and a second cleaning groove module, the fire grate module is secondarily cleaned, so that automatic deashing is realized, the deashing effect is good, and full combustion in the garbage incineration process is realized.