Abstract: A painter algorithm was proposed to better solve the disappearing problem of ore body when ore body was displayed in a graphics equipment. After taking four steps of merging plane polygon, decomposing polygon graphics into triangle graphics, sorting triangular surface treatment and building up triangle graphics for depth, ore body was disposed by the painter algorithm, and hidden line or body warded off by opaque body or other entities in original entities would be not output. When ore body was showed and printed by the graphics equipment, underground mining engineering body would be more realistic.