Semi-hydrogenation of acetylene is an essential step in the olefin industry. In recent years, little attention has been paid to the development of base metal catalysts for use in this process. Nano-nickel catalysts with different loading amounts were prepared by a simple impregnation method in this study. Compared with other non-noble-metallic catalysts, the supported nickel catalyst has a higher activity and selectivity for acetylene selective hydrogenation. The results showed that the conversion and selectivity of the Ni/MCM-41 catalyst were 96% and 87%, respectively, at 240 °C with a Ni loading of 25 wt% and a space velocity of 40 000 h⁻¹. The high activity was attributed to the high metal dispersion and the interaction between the metal and the carrier. In situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) results confirmed the existence of π-bonded ethylene on the metal sites, which improved the selectivity of ethylene.