The invention relates to the technical field of mines, in particular to a protective device of a heat resistant mine furnace frame. The protective device comprises an upper ring, a base and a heat resistant ring, wherein the base is arranged on the lower end of the upper ring, the base and the upper ring are arranged in parallel, the heat resistant ring is arranged in the upper ring, the heat resistant ring is embedded into the inner side of the upper ring, a lower ring is arranged on the lower end of the upper ring, through grooves are respectively formed in the inner sides of the right surfaces of the upper ring and the lower ring, an inner ring penetrates through the through grooves, a chute is embedded into the surface of the inner ring, and adjusting rings respectively sleeve the front ends of the upper ring and the lower ring. When the protective device of the heat resistant mine furnace frame is used by a user, if the size of a protected mine furnace is large, the user can pullthe adjusting rings, the interior of the inner ring can be matched with the chute so as to draw and adjust, the flexible adjustment of the inner ring is utilized, the diameter of the upper ring can beflexibly adjusted along with the inner ring, the user can use the same operating mode for flexibly adjusting the lower ring, and the adjustment is completed.