Abstract: For corrosion acoustic emission test, a low-noise acoustic emission signal conditioning system was designed. The system consists of a charge amplifier circuit, the voltage amplification circuit and the filter circuit. The principle of each part of the circuit is described, and the level of circuit noise is analyzed. The theoretical analysis and experiments show that the op amp input voltage noise of charge amplifier circuit is the main reason that affects the whole circuit noise. In the condition of bandwidth being met, the selection of low-noise op amp can effectively reduce the noise of the signal conditioning system and improve the system’s signal-to-noise ratio.