Abstract: In order to improve the luminance gain of microchannel plate image intensifier, an electron multiplier mechanism-microchannel plate (MCP) was used in low light level image intensifier. The noise mechanism in the MCP was analyzed. By adjusting the energy and angle distribution of the incident electrons at MCP and keeping other MCP parameters unchanged, the optimum operation conditions of MCP for best signal-to-noise ratio were found. The best signal-to-noise ratio of the MCP image intensifier was achieved and the brightness gain of MCP image intensifier was improved.