To study the underwater explosion process of hexanitrohexaazaisowurtzitane (CL-20)-based polymer bonded explosives (PBXs) with and without aluminum powders, two kinds of explosives with aluminum contents of 0 and 15% were prepared.An underwater explosion experimental device was designed, and the images of pressure histories, bubble periods and bubble pulse of shock wave were obtained.The shock wave energy, bubble energy and total underwater explosion energy of two kinds of explosives were calculated The underwater explosion process was well-simulated by the AUTODYN software.Results show that when aluminum content increases from 0 to 15%, the total underwater explosion energy increases from 1.4 times TNT equivalent to 1.7 times TNT equivalent.In the process of bubble pulsation, the light is produced in the bubble of CL-20 based aluminized explosive when the time is from 49.5 ms to 49.8 ms.The peak pressure of aluminized explosives and nonaluminized explosives are 15.16 MPa and 15.51 MPa.The bubble of secondary pressure wave are 2.25 MPa and 2.35 MPa, 50.20 ms and 46.76 ms for the bubble periods.The maximum bubble radius are 67.87 cm and 60.27 cm.The simulation results of aluminized explosives and non-aluminized explosives overpressure are 14.90 MPa and 15.14 MPa.The bubble of secondary pressure wave are 2.16 MPa and 2.27 MPa, bubble period for 49.32 ms and 45.90 ms, 66.32 cm and 58.89 cm for the maximum bubble radius.The shock wave and bubble parameters obtained by calculation are in good agreement with experimental results.