In this paper, the municipal solid waste was used as raw material to produce clean synthesis gas via catalytic gasification and reforming technology and gas purification unit. Nickel based catalysts with different Ce content were prepared by impregnation, then the effects of operating parameters including the oxygen addition, steam addition and Ni-based catalysts' component on synthesis gas generation characteristics were studied. The results indicated that the increasing of oxygen injection and steam supply can improve the carbon conversion efficiency and cold gas efficiency. The addition of metal additives in Ni-based catalyst can promote the decomposition of tar and increase synthesis gas yield. At the temperature of 850 degrees C, equivalence ratio=0.06, steam/carbon ratio=3.6, the clean synthesis gas was produced with hydrogen concentration of 36.78 vol.% and carbon monoxide concentration of 15.29 vol.% via catalytic gasification and reforming process. The cold gas efficiency and carbon conversion rate were 70.17% and 87.17%, respectively. The yield of syngas was up to 0.679m(3)/kg and the tar content was reduced to 17.76 g/Nm(3). After the purification of the gas purification unit, the phenolic compounds were completely removed. The content of SO2 and NOX gas can meet the emission standard of air pollutants, and the average removal efficiency of heavy metal Cr, Pb, Zn, Cu and Hg was above 50%.