In semi一arid mountain area，soil erosion happens mostly on the cultivated slopland and results in poor harvest. Here，a model of having both ecological and economic effect is suggested to control and exploit the cultivated slopland. Water-control，surface-covering and intercropping are the main methods. The research suggests an effective space model about the plants (fruit trees and other crops)and water control methods according to different cultivated slopland.Through this technique 98.6%一99.10.surface runoff will be controlled and 93. 1;一95. 8%of soil erosion be reduced. The yield per unit area will increase respectively 64. 19%and 31. 21;than the control sloping areas with spring crops and areas covered by plastic film.