The conceptions of the knowledge screen generated by S-rough sets are given: f- screen and - screen , and then puts forward - filter theorem, - filter theorem of knowledge. At last, the applications of knowledge separation are given according to - screen and - screen. The conceptions of the knowledge screen generated by S-rough sets are given: f-screen and - screen, and then puts forward-filter theorem, - filter theorem of knowledge. At last, the applications of knowledge separation are given according to - screen and - screen.