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According to the existing problems of no/minimumtill wheat seeding in maize straw covered field in doublecropping system area in the NorthChina Plain, such as residue blockage, low cleanness of seedbed, a strip tillage interrow residue sidethrowing device for antiblocking and seedbedcleaning was developed. The blade tilt angle, tilt line angle and rotary radius were identified as the key parameters influencing seedbed cleaning in the straw throwing process during seeding operation. Through BoxBehnken central composite rotatable design experiment conducted by discrete element method (DEM) simulation, the optimal parameter of blade tilt angle was 25°, and tilt line angle was 30°, rotary radius was 250mm, when torque requirement was 47.2N·m, seedbed cleaning index was 80.5%, and soil throwing index was 15.8%. An seeding and fertilizing opener was designed with a fixed blade in the front which could coordinate with the rotating blade to recut residues for antiblocking; a Vtype board for soil guidance was designed with the angle of 130° which could rebound soil return to seedbed; and an antitwinning board was designed which could increase rotor radius for antiresidue twinning. Field experiments showed that the seedbedcleaning and antiblocking device had a good antiblocking performance, its seedbed cleaning rate was 82.7%, and torque requirement was 2982N·m. The seeding and fertilizing quality satisfied the national and standard agronomy requirement.