In the view of the lack of experimental verification of the 3D imaging sonar-related detection indicators,we carry out an indoor model experiment to explore the effects of different-sized cube and cylinder test blocks,different boundary media and defective cylindrical stakes on 3D imaging sonar.The reseult shows that the 3D imaging sonar system can effectively identify objects of different shapes in centimeters;when scanning for smooth and hard objects,the acoustic signal will be specularly reflected and the effective data cannot be obtained;the defects of 5 cm and above can be effectively identified.The research result may serve as reference for the practical engineering applications.