For a hydropower project, river diversion planning directly decides the dam construction and has a bearing on the diversion standard. The relations between selection of diversion standard and investment, construction duration, risk and its losses of diversion structures should be coordinated. This paper systematically analyzes the controlling factors of choosing diversion standard during initial construction, and puts forward a quantitative analytic method of the factors. By means of multi-objective decision-making theory, a risk model of river duversuib standard during initial stage construction is established. A case study shows that the quantitative analysis and decision model ave effective, and are of great aid to the handling of the relations between the duration, investment and the risk for diversion construction.