Based on XRD, XPS, H2-TPR and other characterization methods and activity evaluation methods, the physical and chemical properties and catalytic activity of CDPF samples doped with different concentrations of La2O3 under hydrothermal aging condition were studied. The results show that with the increase of La2O3 doping concentration, the diffraction characteristic peak shifts a large angle and crystallinity of CDPF aging samples show a trend of decreasing then increasing. La2O3 doping can better inhibit the sintering and distortion of samples during hydrothermal processing and can effectively inhibit the reduction of active quantity, so that the concentration of Pt atoms on the surface of CDPF remains basically unchanged, and the degradation rate of CO, C3H8 and NO catalytic performance decreases. With the increase of doping concentration, the CDPF tends to reverse the trend of ageing.