Work principle of a new anti-blocking mechanism for no-till planting was described. Equations about the trajectory, the absolute velocity and the acceleration of any vertex on the finger wheel were deduced. Associated graphics were constructed by software, and parameters of the device were analyzed. The results indicated that the movement angles δ was chosen between 20°～40°and had great influence on working width compared with radius of the finger wheel. Backward inclined distribution should be adopted for the finger. 