The weighted coefficient optimization method has been applied to a small watershed management in Danjiangkou reservoir area.It gives different weighted coefficients to each objective function and changes multi-objective issue into single objective.The sound answer can be gotten through solving the single objective issue.The method not only simplifies the issue and saves time and labor,but also improves the accuracy of calculations.It is scientific and effective for a given period of time.After planning with it,in view of ecological vegetation,soil erosion can be effectively controlled,natural disasters can be mitigated,and water quality in water source areas can be purified.In view of society and economy,the purpose for farmers' income increment and people affluence may be achieved.