Through the preparation of Pd/ZrO2-Al2O3 catalysts supported by ZrO2-Al2O3 composite oxides, the influence of the preparation of ZrO2-Al2O3 composite oxides on the low temperature CH4 oxidation activity of the catalysts were studied in a continuous flow fixed bed reactor, in order to promote the practical application of ZrO2-Al2O3 in the catalyst for natural gas vehicle exhaust purification, and to clarify the mechanism of the influence of preparation conditions on the conversion activity of the supported catalyst. The results show that the precipitation method can improve the activity of catalyst more than the impregnation method and the peptizing method; When Zr(NO3)4 is used as zirconium precursor and boehmite as aluminum precursor, high catalytic activity can be obtained; The activity of w (ZrO2): w (Al2O3)=10:90 is the highest in series of catalysts with different proportions. The structure characterization of XRD, N2 adsorption-desorption and CO pulse adsorption show that the large specific surface area, pore volume and pore diameter of ZrO2-Al2O3 composite oxides are the key factors to promote the dispersion of noble metal Pd and the conversion activity of catalyst CH4 at low temperature.