The invention provides a natural gas hydrate deposit dynamic triaxial mechanic-acoustic-electrical synchronous test experimental device, and a test method. The natural gas hydrate deposit dynamic triaxial mechanic-acoustic-electrical synchronous test experimental device comprises an acoustic wave receiving device, an acoustic wave transmitting device, and a resistivity testing device. The natural gas hydrate deposit dynamic triaxial mechanic-acoustic-electrical synchronous test experiment method comprises the steps that: step A, a hydrate sample is synthesized; step B, the synthesized hydrate sample is subjected to dynamic loading, and electric-acoustic-mechanical property tests are simultaneously carried out, until the sample is subjected to shearing damage. The invention provides a mechanical response characteristic research of indoor hydrate deposit under dynamic load. With the device and the method, mechanical, electrical, and acoustic parameter synchronous testing of hydrate deposit under dynamic load can be realized. With the test data, a relationship between mechanical parameters and wave velocity can be obtained by fitting.