Currently the quality of concrete entity in water conservancy projects of our province is mostly tested using core-drilling or rebound method, which can hardly detect the inner defects within and lack of timeliness and feasibility. Considering the actual testing environment, this paper uses the nondestructive testing method of GPR (ground penetrating radar) to enhance detection efficiency and achieve quality control of hydraulic concrete objectively and efficiently. This method is based on the reflection law of wave and verifies the location, shape and defection of target object by analyzing the signal receive by GPR. After applying GPR in the quality test of the concrete retaining wall in Wu-Xikou hydro-junction, comparative analysis between the test result of GPR and core-drilling method shows that: the GPR is suit for quality test of concrete retaining wall; the GPR quality test is nondestructive, fast and efficient compared to traditional methods; it’s of great application prospect in concrete quality test in hydraulic engineering.