Abstract: In order to verify the effectiveness of the high-resolution imaging method of the monostatic multiple input multiple output (MIMO) sonar, the tank experiment is carried out, and the expected high-resolution imaging results are obtained. Specifically, two methods, the angle-dimensional high-resolution imaging method and the range-dimensional high-resolution imaging method, are introduced and the corresponding two imaging procedures are given. The first one is based mainly on the virtual array beamforming algorithm, and the second is based on the large bandwidth signal synthesis algorithm. Then, with the use of the designed transmitting signal and the array configuration (the two methods have different transmitting signals and array configurations), an MIMO sonar high resolution imaging system is built for the tank experiment. Finally, via the tank experiment, it is proved that the MIMO sonar can achieve higher angle resolution and better range resolution of target imaging, when comparing with a traditional single-input multiple output(SIMO) sonar.