A measuring and adjusting system and method on uniformity of light intensity of a light source. The measuring and adjusting system on uniformity of light intensity of a light source includes: a light intensity measuring plate; a light source, irradiating light to the light intensity measuring plate; an image acquisition module, acquiring color difference variation image on the light intensity measuring plate; a microprocessor, connected with the image acquisition module and connected with the light source through a control module, wherein the microprocessor compares the color difference variation image with colorimetric criterion internally stored, and obtains the light intensity distribution on the whole surface of the light intensity measuring plate, so as to judge the uniformity situation, and performs adjustment on the light intensity of the light source.