The technology of the booster preparation including particle size distribution and content of the main explosive PETN, mixing and casting temperatures of the PETN and carrier explosive were studied. A new high energy booster was prepared in the study and was initiated by 3.6 g·m-1 detonating cord. Its density is greater than 1.60 g·cm-3，detonation velocity is greater than 7000 m·s-1. It could breakdown 25 mm thick low carbon steel plate. Temperature test and under water pressure test results show that it meets the requirements.