A stress wave reflection imaging(SWRI) method is presented to test and diagnose the complex defects in the concrete structure. The method for collecting stress wavedata and the SWRI algorithm are used to detect the specimen with embedded complex defects, the corresponding pre-stack migration images are obtained by usingdifferent numbers of collected data. Results show that with the increase of the number of stress wave, the clear imaging region became broader and the image of the defect became clearer. Using adequate stress wave signals in prestack migration processing, there will be little error in SWRI diagnostic results, thus meeting accuracy requirements on engineering practice.