The invention provides an economic crop belt for cutting down pollutants in a ditch in an irrigated region. The economic crop belt comprises an economic crop growing region, a vertical weight lifting repair region, a transitional spacer region and fixing piles, wherein the economic crop growing region is connected with the vertical weight lifting repair region through the transitional spacer region, and the fixing piles are used for fixing the economic crop growing region, the vertical weight lifting repair region and the transitional spacer region at designated spots on one side of the ditch. According to the economic crop belt, organic pollutants and nutritive salt in farmland tail water are removed through assimilation and absorption as well as adsorption and consumption of water planting economic crops and light ceramic particles in the economic crop growing region as well as biozeolite in the vertical weight lifting repair region, the plants growing in the economic crop belt has economic benefits while giving play to ecological benefits simultaneously, the maintaining enthusiasm of farmers can be strengthened, and the generalization performance is strong. During the irrigation period, the device can be put away and put on the ditch to guarantee the water flow speed of the ditch, has the advantages of being low in cost, simple and attractive, economical and environment-friendly, and obvious in effect, and is suitable for cutting down the pollutants on a farmland surface source.