To investigate the performance of microchannel plate (MCP) image intensifiers, the electromagnetic simulation software CST Studio Suite is used to simulate and analyze the effects of changes to the parameters of MCP image enhancers on their gain and spatial resolution. Simulation results show that the working voltage of MCP has the greatest effect on MCP gain, and an increase in working voltage causes the gain to increase exponentially. Changes to the phosphor screen voltage and bias angle significantly affect spatial resolution. An increase in phosphor screen voltage significantly improves spatial resolution, but an increase in bias angle leads to a significant decrease in spatial resolution. The gain and spatial resolution of the MCP image intensifier can reach a relatively ideal theoretical simulation result when the working voltage, phosphor screen voltage, bias angle, and depth of the output electrode are 890 V, 6000 V, 5°, and 0.021 mm, respectively. These results provide a good reference for designing MCP image enhancers with better performance.