Grinding Method of Honeycomb Structure

There is disclosed a grinding method of a honeycomb structure which can enhance a contour accuracy of a processed surface, and form "a honeycomb structure having a ring-like bulge portion on an outer periphery, the bulge portion being formed into a tapered shape" in a short time. A grind processing member having an outer peripheral surface, a first grinding wheel tapered surface and a second grinding wheel tapered surface and rotating around a central axis grinds a joined honeycomb segment assembly rotating around a central axis, and the above respective surfaces of the grind processing member form a first ground region, a second ground region, a center ground surface, a first tapered surface and a second tapered surface, to prepare the honeycomb structure including a cylindrical honeycomb base material, and a ring-like bulge portion "which surrounds an outer periphery of the honeycomb base material, protrudes from the outer periphery of the honeycomb base material toward the outside in a flange manner, and has the first tapered surface, the second tapered surface and the center ground surface" in the grinding method of the honeycomb structure.