To improve the explosion energy of nitric ester explosive, boron-containing hydrogen-storage-alloy (Mg(BH_x)_y) was added into nitric ester explosive. The explosion energy and after burning effects of nitric ester explosive with Mg(BH_x)_y were studied by underwater explosion test and explosion test in air. Results show that Mg(BH_x)_y can significantly improve the explosion energy of nitric ester explosive. In explosion test in air, Mg(BH_x)_y is decomposed, and the decomposition products are involved in the detonation reaction. In underwater explosion test, after adding Mg(BH_x)_y, the explosion energy of the nitric ester explosive is increased by 17.56%, and the nitric ester explosive with Mg(BHx)y has an obvious after burning effect.