The agronomic planting technique of garlic with its bulbil facing upward accords with the growth characteristics and it can achieve a significant effect of increasing yield. The garlic planting machinery on the market is generally difficult to meet the agronomic needs of vertically planting. Based on the achievements in transplanting machinery and using a noncircular gear rotary transplanting mechanism as the coreworking component, a vertically transplanting mechanism for garlic based on agronomic requirements was developed. Firstly, the mathematical model of the transplanting mechanism was established by the D-H transformation method, which was commonly used in robotics. With the analysis of the trajectory and posture of artificially planting garlic, a total number of twelve optimization goals required by the transplanting mechanism were determined. Since the optimization goals had characteristics of fuzzy, nonlinear and strong coupling, the parameterguided heuristic optimization method was used in the optimization process, and the GUI humancomputer interaction optimization software was written under the Matlab software platform. After optimization, a set of design parameters meeting the requirements of the goals were calculated. Referring to the obtained optimizing design data, the contour shape of the noncircular gears were generated in KissSoft software. The topdown design method was used to parametrically design the transplanting mechanism by CATIA software, and simulation verification of the transplanting mechanism was carried out by using ADAMS software. Finally, an experimental bench for the garlic vertically transplanting mechanism was designed, and the multifactor combination experiment was carried out with the transplanting depth, the rotation speed of the mechanism, and the matching speed ratio as the experimental factors. The quadratic regression orthogonal rotation combination design method was used to arrange the experiment, and the regression equation of the influence of each experiment factor on the bulbil angle of garlic after planting was obtained. The results showed that when the transplanting depth was 17mm, the transplanting speed was 29.6r/min, and the matching speed ratio was 100%, the average vertical angle of garlic bulbil would be 8.54°. When the transplanting speed was increased, the verification result was also in the desired range of agronomic requirements. The research results can provide a reference for the development of new garlic planting machinery and other transplanting mechanisms with complicated trajectory.