The invention discloses a circulation mechanism for storing cylindrical mold standard parts. The circulation mechanism comprises a rectangular box body, a placement groove is formed in the lower end surface of the box body, a plurality of prismatic partition columns distributed in an array are arranged in the placement groove, a partition plate abuts against the lower end surface of the box body,a sinking table is formed on the upper end surface of the partition plate, and the bottom surface of the sinking table is provided with prismatic partition blocks; limiting plates are formed on the parts, on the two sides of the sinking table, of the upper end surface of the separation plate, inserting grooves are formed in the positions, on the two sides of the placement grooves, of the lower endsurfaces of the box body, and the limiting plates are inserted into the inserting grooves; a cover shell is fixed on the part, on one side of each inserting groove, of the side wall of the box body,a baffle is arranged in each cover shell, a pull ring is formed in the middle of each baffle, and the part, on the two sides of each pull ring, of each baffle abuts against a pressure spring; and twopositioning rods are formed on the two sides of the side wall of each baffle, two positioning holes corresponding to the positioning rods are formed in the two sides of each limiting plate, and the positioning rods are inserted into the positioning holes respectively. According to the circulation mechanism, stacking operation of the mold standard parts can be realized conveniently, and the mold standard parts can be conveniently stored in the box.