Abstract: According to the sound field characteristics of single and double shells, the numerically calculations of the change of sound pressure gain of the shells before and after attaching different sound-reflection baffles or soundabsorption baffles are performed in this paper. The influence of acoustic baffles on the sound field near the shell surface is analyzed, and the abilities of different types of acoustic baffles to solve the positive and negative gain mutation problem of double shells at some frequency points are investigated. The calculation results show that the acoustic baffle has obvious effect on improving the sound pressure gain of the front surface of the double shell, and the multi-layer rubber composite sound-reflection baffle is superior to the foam sound-reflection baffle, and the soundabsorption baffle has more advantages than the sound-reflection baffles on the whole. For a single shell, no baffle is better from the perspective of near-surface sound pressure gain.