The seeding drill unit is mainly composed of working parts which include a seed and fertilizer opener, a seeding apparatus, a soil covering and pressure device, et al. The seeding operation is carried out, and when working under the condition of wet clay. The backfill performance of the fertilization shovel is weak, because of the soil fluidity is poor. The phenomenon of “burn seed” was occurred due to seed and fertilizer at the same seed bed. In addition, to ensure that soil has sufficient time to return the fertilizer ditch, the operation speed of the implement cannot be too fast. Moreover, the mechanical operation of highefficiency seeding and fertilization is restricted. Aiming at the existing problems and the background of the existing research, a forced soilreturning device was designed on the basis of the principle of brachistochrone. The optimal structure and the parameter combination of the forced soilreturn device were explored through the combination of theoretical analysis, the virtual simulation and the test, and the threefactor threelevel orthogonal test method were applied. Taking the working speed, distance of returnbaffle and included angle of returnbaffle and soil surface as the test factors. The soil backfill rate and the passthrough property of drill unit were used as evaluation indexes. And the related parameters affecting the operation performance of the forced soilreturning device were tested and optimized. The test results showed that for the soil backfilling rate Y1, the working speed and backflow baffle spacing had a significant effect on it (P<0.01), and the influence of the angle between the backflow baffle and the surface was not significant (P>0.05). To the passthrough property of drill unit Y2, the backflow baffle spacing and the angle between the return baffle and the surface were extremely significant (P<0.01), and the working speed had a significant effect on it (0.01<P<0.05). When the parameter combination was 1.5m/s, the return baffle spacing was 112mm, the angle between the return baffle and the surface was 60°, and the soil backfilling rate was 91.2%. There was no blockage of the drill unit during the operation. The comparison test showed that the optimized speedreducing line forced earthreturning device, soil backfill performance was increased by 16.5%. The forced earthreturning device designed based on the principle of the brachistochrone method can improve the soil backfilling rate without reducing the passability of notillage sowing, and effectively avoided the seeding of the seedbed due to poor fluidity in the soil wetadhesive environment. Tillage planter provided theoretical reference and technical support for high quality and high efficiency operation.