The technology of rice potted seedling transplanting can realize high yield, which has advantages of shallow planting, less damage on the seedlings, fast recovery, low and early tiller and high efficiency. Foreign rice potted seedling planting technology is not suitable in China for complicated structure and high cost problem. And there are defects for domestic transplanter with low efficiency, heavy vibration, and tossing transplantation with uncontrollable seedling perpendicularity. A new type of rice potted seedling transplanting mechanism of noncircular planetary gear train with one uncompleted noncircular gear, six noncircular gears and two transplanting arms was presented on the basis of analysis of the shortcomings of the existing rice potted seedling transplanter at home and abroad. The working principle of rice potted seedling transplanting mechanism was introduced, and the parameter optimization method of humancomputer interaction optimization was proposed. The analysis and optimization software of the transplanting mechanism was selfdeveloped and used to obtain a set of mechanism parameters for realizing better working trajectory and posture. The virtual prototype and physical prototype of the transplanting mechanism were developed to conduct virtual kinematic simulation analysis and kinematic tests with highspeed photography technology on the testbed, and the static trajectory and posture of the seedling needle of the transplanting arm were obtained. The results of the simulation analysis, bench test and theoretical analysis are almost consistent, which shows the correctness of the design method and results and the application feasibility of the transplanting mechanism.