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On the base of corn insert plot hill-drop planter, in the light of sowing performance of passive duckbill opening is greatly affected by the fluctuation of ground level, a strong row-strong open metering device was designed, which is mainly composed of conjugate cam, strong platoon-strong open metering device. The sowing process of forward speed compensation device of corn insert plot hill-drop planter was analyzed to determine the key sowing time points. The displacement calculation of two kinds of movements of connecting rod and fetching seed wheel and opening forcibly of duckbill were carried out emphatically. According to the calculation results with reverse calculation method, the main cam profile of the conjugate cam was determined. A uniform rotation wheel can improve the rate of movement of the cam follower, and the motion law of cam follower was determined by calculation. And test results showed that transmission of forced sowing and forced opening for corn direct seeding machine was stable, which can complete picking and seeding corn, and duckbills when metering did not clip soil, and film hole was small, and there were no problem that duckbills pick film, tear film, etc. The hole rate of corn insert plot hill-drop planter was 1.8%, cavity and seed number of qualified rate was 95.3% and planting under film depth pass rate was 88.1%, thus the design of strong seeding corn-strong opening duckbill of insert plot hill-drop planter met the design requirements and agronomic techniques of corn planting.