Traditional outer groove-wheel fertilizer apparatus (OGWFA) with the straight tooth exists the problem of breakage and pulsation in the fertilizing process. A new type of OGWFA with the helical tooth has been designed to solve this problem, and the amount of fertilizer can be adjusted. The helix angle of the helical tooth has been optimized by theory analysis and DEM simulation. It reveals that the helix angle should be ranged from 34.4° to 68.8°. The performances of the OGWFA with the helical tooth and the straight tooth have been compared by the bench experiment. It indicates that the variable coefficient and the breaking rate of the OGWFA with the helical tooth are lower than these of the OGWFA with the straight tooth.