Ni/MgO−Al 2 O 3 multifunctional catalysts were synthesized and applied to toluene reforming with a microchannel reactor to obtain hydrogen-rich syngas and lowest deactivation by carbon deposition. These catalysts were characterized by inductively coupled plasma-atomic emission spectroscopy, N 2 adsorption−desorption, X-ray diffraction, H 2temperature programmed reduction, NH 3 -temperature programmed desorption, and transmission electron microscope-energydispersive spectrometer. The results showed that MgO−Al 2 O 3 support had the largest Brunauer−Emmett−Teller surface area and formed a steady MgAl 2 O 4 spinel structure after 800 °C calcination, which is conducive to preventing Ni sintering, increasing Ni dispersion, and thus improving catalytic activity. Less than 15% Ni loading maintains a high dispersion on the MgO−Al 2 O 3 support, but 20% Ni loading caused a sharp decline in the surface area and dispersion effect, which is due to Ni sintering and pore plugging. Meanwhile, 15% Ni/MgO−Al 2 O 3 shows a higher catalytic activity and excellent stability than others. In addition, the microchannel structure increased the surface area-to-volume ratio and enhanced the heat-transfer coefficient, hence had a prominently promotive effect on the catalysts utilization efficiency.