Abstract: The noise factor, which is the main factor affecting the noise performance of image intensifier and can accurately reflect the noise characteristics of the microchannel plate, is the ratio of the input signal to noise ratio and the output signal to noise. According to definition of noise factor of microchannel plate and test principle, filmed MCP test system was established in order to study the technical way to reduce noise factor of MCP. The input surface of the MCP was covered with ion feedback film, which had a great impact on the noise factor of the MCP. Hence, noise factor of filmed MCP and un-filmed MCP were measured respectively, and the noise factor with different material, different channel pore, different incident electrons and MCP voltage were measured too. Relationships between noise factor and incident electron, noise factor and MCP voltage was obtained. That was valuable to reduce the noise of filmed MCP.