To improve the storage stability of potassium borohydride(KBH₄), sodium borohydride(NaBH₄) and lithium aluminum hydride(LiAlH₄), KBH₄ and NaBH₄ were coated by paraffin via solvent-nonsolvent method and LiAlH₄ was coated by naphthalene via recrystallization. The surface coating stafas of the samples was studied by SEM, FTIR and XRD and the combustion properties of the propellants added into coated sample were tested by an Infrared Thermometer. Results show that KBH₄, NaBH₄ and LiAlH₄ are completely coated and the coating stafas of NaBH₄ is the best. The combustion properties of propellant added with coating-NaBH₄ sample are significantly improved and the burning rate is increased by more than 5%.