The invention relates to an optical-microwave common image resolution evaluation bar target and a construction method thereof. The optical-microwave common image resolution evaluation bar target comprises a cement board target bar, a coarse gravel area, a target substrate layer and the like, wherein the target bar is a reflecting material capable of presenting the difference of black and white contrast in an optical or microwave imaging loading image; different reflecting materials can be laid on the target substrate layer for the purpose that the target substrate serves as a substrate, so that the smoothness of the target surface is guaranteed, and long-time running is facilitated. The optical-microwave common image resolution evaluation bar target has the benefits that optical and microwave remote sensing loading space resolutions can be evaluated at the same time; the optical or microwave remote sensing image with the resolution of 0.1-5 meters can be evaluated; the resolutions can be obtained without calculation; the geometrical shape of the target cannot be influenced by snow, rain and frost, and the target is suitable for outdoor long-term use; the target has good self-cleaning capacity, and dust on the surface of the target can be washed by rainwater and wind; concrete boards and gravels are low in outdoor degeneration speed, so that the maintenance cost required for normal operation is greatly reduced.