Outer row of wheel fat paddle is one of the most widely used fertilizer, the current structure of the outer row wheel fat pad and a single geometric structure, can not be applied to different fertilizer particle fertilizer demand, a direct impact on the fertilizer effect. EDEM is currently one of the most effective methods for particle simulation. The three-axis size of the fertilizer particles was obtained by means of measurement and statistics. The shape of the fertilizer particles was approximated by the sphere. The EDEM model of the fertilizer particles and the outer tank runner was established. By changing the structure size of the sheave, Simulation was carried out to analyze the fertilizer discharge characteristics of the outer tank wheel economizer. The 3D printing design was designed to validate the simulation results through the bench test. The results showed that the groove radius and sheave speed had a significant effect on the amount of fertilizer application, which had a positive linear correlation. The helix angle had no significant effect on the amount of fertilizer application (P> 0.05). The relative error between simulation results and experimental results was 0.85% -15.98 %, The average relative error is 7.21%. The EDEM simulation model established in this paper is accurate and has practical engineering application value.