In order to meet the requirements of stricter emission regulations in the future, one-dimensional GT-Power and three-dimensional CFD simulation softwares were used to build the onedimensional  and three-dimensional physical models of spark ignition methanol engine by taking a traditional diesel engine as an example. By adjusting the ignition timing, the effects of different equivalent ratios and EGR rates on engine emissions were analyzed. The results show that CO emission decreases first and then increases, NO_x and CO₂ emissions both decrease, and the emissions of unburned methanol and formaldehyde are almost close to 0 with the delay of ignition timing. When the ignition angle is -10°ATDC, the emission is better. With the increase of equivalent ratio or EGR rate, CO emissions increase, NO_x emissions reduce, and the emissions of unburned methanol and formaldehyde are almost close to 0. CO₂ emission reduces in the end, but first increases with the increase of equivalent ratio.