A compound represented by formula I, or a pharmaceutically acceptable salt, solvate, polymorph, enantiomer or racemic mixture thereof, wherein, R1 and R2 are independently hydrogen, -OH, alkyl, -CF3, -OCHF2, -OCF3 or halogen,R3 is cycloalkyl, -OCH2CF3, -OCH2CHF2, -OCH2CH2F or -OCH2CH3,R4 is hydrogen, -OH, -O aryl, -OCH2 aryl, alkyl, cycloalkyl, -CF3, -OCHF2, -OCF3, -OCH2CF3, -OCH2CHF2, -OCH2CH2F or halogen,A is -CX1X2, wherein X1 and X2 are independently H, F and Cl, and when both X1 and X2 are H, R3 is other than -OCH2CH3. The compound has an activity of inhibitors of sodium-dependent glucose transport protein. A method for preparing the compound. A pharmaceutical composition comprising the compound. A use of the compound and pharmaceutical composition thereof in the preparation of medicaments of SGLT2 inhibitors for treating a disease of interest.