In order to solve the problem of low upright rate of traditional machinery, a method for determining the garlic clove orientation based on capacitive detection technology was proposed. There were differences in morphological structure between the bud and the root: under the same width, the volume of the bud was smaller than that of the root. The feature was exploited and converted to an average dielectric constant difference to determine the orientation of the garlic clove by detecting the capacitance. The feasibility of the method was verified based on the electric field analysis of ANSYS in the research process. In addition, the corresponding bud adjustment device was designed. Orthogonal tests took the short axis radius, long axis radius, and bottom angle of the device as the test factors and the upright rate as the test indicators, and the test data were analyzed by Design-Expert 11.1.2.0 software to obtain the order of influence of each factor on the index value. The results showed that when the bottom angle, short axis radius, and long axis radius were 80°, 22.99mm, and 27.79mm, respectively, the device performance was optimal and the theoretical upright rate was 96.6%. The test verification of the optimized factors was basically consistent with the optimized results. With the pole plate parameter as the test factor and the signal to noise ratio as the test indicators, the test data showed that the device performance was optimal when the pole plate parameter was 45mm×8mm×0.10mm. The prototype test was carried out with Jinxiang and Cangshan garlic cloves, and the qualified rate was 95.0%, which met the requirements of garlic sown. The research result can provide support for the application of capacitance detection technology in precision sowing equipment.