Abstract: Aiming at the problem of low sowing accuracy and low sowing qualification index of existing corn seeders, a kind of corn precision sowing compound operation machine is designed. The working principle and main technical parameters of the sowing composite operation machine are expounded, and the work of rotary tillage, fertilization, precision sowing, mulching and suppression of seedlings can be completed at the same time in one entry. Seedling belt rotary tillage was selected, and the operation motion state of rotary tillage mechanism was analyzed theoretically, and the circumferential arrangement of rotary tillage knives was determined to meet the requirements of protective tillage and improving sowing accuracy. The overall structure of the parallelogram profile mechanism was determined, and the force and size parameters were analyzed, and the rod length of the profiling mechanism was obtained through calculation, to make the sowing cell have enough profiling to ensure the consistency of the sowing depth. The air-suction seeder was selected, the structure of the air-suction seeder was determined, and the maximum speed of the seeder was calculated, which could achieve the purpose of precise seeding. The field test in Huang-Huai-Hai area showed that when the operating speed of the seeder was 4 km/h and the speed of the seedling belt rotary tillage mechanism was 280 r/min, the passability of the machine was good, the pass rate of seedling belt width was 93. 5%, the qualification rate of sowing depth was 93. 1%, the pass rate of grain size was 93. 5%, the replay rate was 5. 9%, the missed broadcast rate was 3. 3%, and the coefficient of variation of qualified grain size was 15. 64%.The performance indicators meet the agronomic requirements.