The core components of Image intensifier is microchannel plate (MCP) and fluorescent screen component. The present paper deeply studies output signal-to-noise ratio (SNR) characteristics of MCP and fluorescent screen component. A tester system using to the evaluation of characteristics of the output SNR of MCP and fluorescent screen component, consists of a vacuum system, a surface electron source, mechanical mechanism components ,a high-voltage power supply system, a signal processing system, communication interfaces, a data acquisition and control system, computer system, and testing software. a hot cathode used as an electron source, generates a surface electron flow to provide the input signal. A photomultiplier tube is used to detection faceplate output brightness of the light spot. Then, the output SNR of MCP and fluorescent screen component is processed with a combination of methods of the hardware filter and digital filtering software. The output SNR of MCP and fluorescent screen component is measured under different conditions, and the results are analyzed. This test system Provide a technical to promote the image intensifier research, and experience to testing other parameters or in other areas of research.