There are many risk factors and uncertainties in the slope pre-stressed anchor engineering construction in a contract section of Zangmu hydropower station， so the project management is very difficult. The risk assessment index system was established, index weight analysis was conducted by using three-demarcation method and AHP， fuzzy comprehensive evaluation model was introduced, the managers and experts’ experience was changed from qualitative to quantitative, and quantitative assessment of the project risk was made with the result of “high risk”. All of the above offered the basis for further project management scheme establishing.