Deepfertilization technology of liquid fertilizer is a kind of agricultural technology which can apply liquid fertilizer accurate quantitatively in deep soil near the roots of crop according to the distribution characteristics of soil nutrient and crops. A type of picking hole mechanism of deep liquid fertilizer with planetary Bezier gears that was designed by using a fitted Bezier curve as a noncircular gear pitch curve was proposed. Taking picking hole mechanism as the research object, a dynamics model was established, thus, the variation law of force both on axle centers and meshing points of gears in a working cycle due to the changing of the rotaryangle of planetary carrier was obtained using Visual Basic software. Soil bin dynamics test bench was also set up. Dynamics properties of picking hole mechanism, spray fertilizer needle and bearing were determined with rotary speed of 40r/min, 60r/min and 80r/min, moving speed of soil bin of 0.8m/s and soil firmness of 0.4~1.0MPa. Experimental results show that vibration of picking hole mechanism was increased with the increase of rotary speed of planetary carrier. With the 180° rotation angle as the center, the reaction force of bearing was symmetrically distributed. The test results were consistent with theoretical analysis, which verified the correction of theoretical models and the feasibility of test method. This research provides a theoretical foundation to dynamic balance control of the liquid fertilizer applicator during highspeed operation, and lays a foundation for the further design of high speed and lightduty machine. 