The 2BYD-6 rape seeding machine was designed by Hunan Agricultural University, which install the T245 type rotary tiller blade with 20 left curved blades and 20 right curved blades arranging with Archimedes spiral. The rotation radius of the blade is 0.287 5 m. Based on the classical mechanics, a calculation method had established for rotary tillage’s soil cutting volume as well as the force balance equation. The torque for cutting and throwing soil was calculated, respectively. A power consumption model for rotary tillage was established to analysis the relationship between the working parameters of the rape seeding machine and the rotary tillage power consumption. The results showed that the force in horizontal direction was increases with an increase in the rotation speed and the machine's forward speed. The force in vertical direction fluctuated little with the rotation speed and the forward speed. Under the forward speed of 0.4, 0.5, and 0.6 m/s, the rotary tillage power consumption has a linear relationship dependent on the rotation speed. The fitting equations were y=–4.481+0.101 6x, y=–4.947+0.109 0x, y=–4.466+0.113 0x. Compared the EDEM simulation results, the errors are from 2.51% to 6.69%, under the forward speed of 0.4 m/s to 0.6 m/s and the rotation speed of 100 r/min to 160 r/min.