An inflatable divergent Fresnel lens and non-imaging CPC based non-tracking high concentration ratio solar concentrator system comprises a flexible domed divergent Fresnel lens, and an inflatable non-imaging CPC concentrator with a domed transparent top cover and a flat transparent bottom cover. Where, the flexible domed divergent Fresnel lens is attached onto the said domed transparent cover of the said inflatable non-imaging CPC concentrator. When in operation, the oblique incident sunlight including beam light and diffuse light onto the domed divergent Fresnel lens, is deflected to change its direction, and consequently change its original incident angle relative to the said CPC concentrator from large to small, then eventually fall in the acceptance half-angle to be concentrated by the said CPC in large concentration ratio.