Aiming at the problem of poor tobacco growth quality caused by uneven fertilization during tobacco planting, this paper designs an optimized tobacco planting ditch fertilizer machine, which can simultaneously complete the ditching and fertilization process before tobacco planting. In order to make the fertilizer guide structure achieve uniform delivery, the speed, outer diameter, and pitch of the fertilizer guide structure are used as the changing factors, and the fertilizer guide uniformity of the fertilizer guide structure is used as the index. EDEM simulation analysis is used to optimize the parameters of the fertilizer guide structure. Through EDEM simulation analysis and field test verification, it is concluded that the outer diameter of the screw (with the inner diameter unchanged) has the greatest influence on the uniformity of the discharge of the fertilizer guide structure. And under the design parameters of this article, when the outer diameter is 80mm, the pitch is 30mm, the screw inner diameter is 30mm, and the sleeve inner diameter is 110mm, the discharge uniformity of the fertilizer guide structure is the best.