The invention discloses a rotary double-post molding mechanism, which pertains to a double-post device of a molding machine and solves the existing technical problems of high labor intensity and relatively low production efficiency. The invention comprises a machine rack (1), a bolt cylinder (2), an A template (3), a large panel (4), a gear wheel (5) and a turning table (6). A central hole of the large panel (4) is provided with a plane bearing (13), the turning table (6) is arranged above a radial sliding bearing (7) and the gear wheel (5) is fixedly arranged under the turning table. In addition, a motor seat (15) is arranged on the large panel (4), a hydraulic pressure motor (8) is arranged on the motor seat, and a pinion (14) is arranged above the hydraulic pressure motor. The pinion (14) engaging with the gear wheel (5) realizes that the turning table rotates 180 degrees forwardly and reversely and takes a column (9) as the center, the bolt cylinder (2) is arranged under the large panel (4), and a bolt hole is arranged on the gear wheel (5). The rotary double-post molding mechanism improves qualified rate of the finished products and production efficiency and prolongs service life of the whole set of equipment.