The motion equation of mulch slit cutting mechanism was deduced from combining the knife motion equation and the rotary type transplanting motion equation. The motions of the planting finger and the knife were simulated to determine the theoretical mulch slit length and planting position. Results showed that theoretical slit length is longer when planting depth is deeper, and shorter when hill spacing is wider. The planting position varies from the center of the slit to the front. Tests on the sliding soil bin, laid with film, showed that the tip of knife reached the film earlier than the planting finger, all slits were straight, and the planting position was similar to the theoretical value. Therefore, the possibility of making slits while transplanting was confirmed.