A multiplexing device for an image display includes: a light source part which has light source modules which irradiate laser beams having different wavelengths; a multiplexing part which multiplexes laser beams irradiated from the respective light source modules; optical fiber parts, each optical fiber part including a light-source-side optical fiber which has one end portion thereof connected to the light source module and a multiplexing-side optical fiber which has one end portion thereof connected to the multiplexing part; and a plurality of connecting parts, each connecting part connecting the light-source-side optical fiber and the multiplexing-side optical fiber with each other. The connecting part can change a distance between the other end portion of the light-source-side optical fiber and the other end portion of the multiplexing-side optical fiber which face with each other.