A copolymer comprising anthracene and benzoselenadiazole, preparing method and uses thereof are disclosed. The copolymer is represented by formula (I), wherein n is a natural number from 10 to 1000, a is 1 or 2, b is 0, 1 or 2, X, Y are O, S, Se, SO2, N—R4 or R5—Si—R6; R4, R5, R6 are selected from C1-C20 straight-chain, branched-chain or cyclo alkyl or alkoxy; R1, R2 are unsubstituted, monosubstituted or polysubstituted functional group Ar1, and said Ar1 is selected from hydrogen, halogen, cyano, substituted or unsubstituted C1-C40 straight-chain or branched-chain or cyclo alkyl, substituted or unsubstituted aryl or heteroaryl; R3, R7 are unsubstituted, monosubstituted or polysubstituted functional group Ar2, and said Ar2 is selected from hydrogen, cyano, substituted or unsubstituted C1-C40 straight-chain or branched-chain or cyclo alkyl, substituted or unsubstituted C1-C40 alkoxy, substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C6-C40 aralkyl, substituted or unsubstituted C6-C40 aryl alkoxy.