The correct choice of subcontractors (SCs) increases the overall success of a construction project for general contractors (GCs), but at present,there is not a uniform selection process or method. Bused on the characteristics of water conservancy and hydroelectric projects, from the perspective of construction GCs, evaluation index system of selecting SCs is designed ,the DEA cross-evaluation model and its application are given. Combined with engineering example, the model is tested.lt is proved that the DEA model of SCs selection overcomes the current strong subjective wishes weaknesses of GCs selecting SCs in China, the evaluation results are more effective and more objective in reality, and it provides a quantitative scientific decision-making approach to SCs selection.