Biomass combustion product rice husk ash was selected as the carrier, and Ni-Mg/RHA catalyst was prepared by co-impregnation method. The catalytic performance of Ni-Mg/RHA for steam reforming of toluene was studied using toluene as a model compound of biomass tar. The effects of Ni and Mg loadings, reaction temperature and S/C ratio on toluene conversion and gas product composition were investigated in a fixed-bed reactor. The catalysts before and after reaction were characterized by XRD, BET and SEM.The experimental results show that RHA as a support of single metal Ni-based catalyst has a certain catalytic activity;The activity and resistance to carbon deposition of Ni/RHA catalyst were significantly improve by that formation of NiMgO solid solution active center after the loading of MgO, and the catalytic activity and the resistance to carbon deposition of Ni/RHA catalyst were optimal when the Mg loading amount was 6wt%, and the toluene conversion was as high as 98.6%；The optimum reaction temperature of 3Ni-6Mg/RHA is 700 ℃, S/C is 3, and the catalyst has good catalytic stability. The feasibility of using rice husk ash as the support of nickel-based catalyst in the presence of MgO was proved.