The invention relates to the technical field of seedling planting, and particularly relates to a weed treatment device for seedling planting. The technical purpose is to provide the weed treatment device which is used for seedling planting and saves time without the need to manually cut up weeds. In order to achieve the above technical purpose, the weed treatment device for the seedling planting includes a cart and the like. A cutting device is arranged at the left side of the top of a cart plate of the cart, a collecting device is arranged at the right side of the top of the cart plate of thecart, and a collecting part of the collecting device is located below the cart plate of the cart. According to the weed treatment device, the weeds are cut by the cutting device, the cut weeds are collected by the collecting device, and a crushing device is arranged for crushing the weeds, so that the time is saved, and there is no need to manually cut up the weeds.