Owing to the complicated environments, the service life of bag-filter or electrostatic-bag composite precipitators with polyphenylene sulfide (PPS)-based bag-filter materials is greatly deviated from the ideal time. In this paper, the structural transformation of PPS-based bag filter materials collected from the coal-fired power plants with different loading units were investigated systematically. As the SO2 content increases, the surface evolution of PPS fibers from smoothness to crack occurs.The major reason for the failure of PPS-based bag filters is that working temperature (T) often passes through acid dew gas point (Ta), and the SO3 would be produced during the condensing of H2SO4 when T is lower than Ta. This work discloses the actual structural evolution of PPS and some corresponding rules under the complicated corrosive gases with high temperatures, which provides a guidance for prolonging the service life of PPS-based bag filters during the usage of coal-fired power plant