Abstract: The glimmer intensifier is core component of low light level night vision device, and it is the determining factor of glimmer night vision complete machine performance and price. Since the glimmer intensifier works under weak light , it is the light energy amplifier. Brightness gain is a key parameter of the glimmer intensifier electro-optic property assessment, which effects the complete machine performance directly, therefore, research on the brightness gain test technology of image intensifier has great significance. This paper introduced the principle and equipment of third generation glimmer intensifier brightness gain measurement, and carried on the uncertainty evaluation of the measurement result.