In order to research polyvinyl alcohol (PVA) fiber concrete failure mechanism, the acoustic emission (AE) monitoring technique was proposed. Through three-point bending experiment, flexure strength of PVA fiber concrete and AE characteristic signal has been obtained. According to the correlation diagram of AE amplitude, count and energy, the degeneration reason of flexural strength and damage mechanism for corroded PVA fiber concrete was explained. At last, NDIS-2421 quantitative evaluation criterion was used to assess the damage of concrete specimen, and the function of PVA fiber in corroded and uncorroded concrete is analyzed. Furthermore, clearance factor of AE signal is computed, it is found that bending damage of PVA fiber concrete is divided into three stages obviously, and clearance factor of uncorroded PVA fiber concrete is relatively uniform.