To solve the problem of high impact sensitivity, long preparation technological process and agglomerate of superfine RDX etc. existed during preparation of superfine A5 booster explosive by aqueous suspension coating technology, superfine A5 booster explosive was prepared with the solvent evaporation technology using stearic acid (SA) as insensitive agent, absolute ethyl alcohol as solvent and dispersant. The scanning electron microscope (SEM) observation, impact sensitivity test and SA content determination to samples prepared by two kinds of processes were performed. Results show that the superfine A5 booster explosive is coated more evenly, its particle size is 2.17 ~10.72 μm. Compared with superfine A5 booster explosive obtained by an aqueous suspension coating technology, the characteristic drop height of impact sensitivity of superfine A5 booster explosive obtained by the solvent evaporation technology increases from 18.62 cm to 32.69cm and loss rate of SA decreases from 0.120% to 0.046%, which showing a low sensitive and more exactly component controlling.