The existing solid particle detection methods for the liquid-solid flow suffer from various degrees of defects. For this reason, the acoustic emission detection device for the liquid-solid two-phase flow is proposed and developed, and the indoor evaluation tests are carried out. Using the software developed by us, the information of sand concentration and size is extracted from tests under laboratory conditions. The results show that the power spectrum amplitude of the sand acoustic emission increases with the sand mass content under a fixed sand size, but decreases with the increase of the sand size under a fixed sand concentration.