The static finite element analysis and structure optimization were performed for 2SF-0.6 type fertilizer spreader by using the Simulation software. A series of key structure parameters of the components were obtained as following: thickness of the fertilizer box wall is 1 mm, diameter of transmission shaft is 6 mm and thickness of the rectangular steel pipe in the frame is 2 mm. By modal analysis of the optimized structure, it can be concluded that the transmission shaft’s rotation speed should avoid the range of 975.84-1 463.76 r/min. The optimized fertilizer spreader can effectively prevent the resonance because the 10th modal vibration frequency of the unit is far away from the rotary vibration frequency of external excitation source, i.e. about 20.33 Hz.