Disclosed is a compound of formula I, or a pharmaceutically acceptable salt, solvate, polymorph, enantiomer or racemic mixture thereof, wherein R1 and R2 are each 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 each independently H, F and Cl, and when both X1 and X2 are H, R3 is not —OCH2CH3. The compound has an activity of inhibitors of sodium-dependent glucose transport protein. Also disclosed is a method for preparing the compound, a pharmaceutical composition comprising the compound, use of the compound and pharmaceutical composition thereof in preparing medicaments of SGLT2 inhibitors and treating related diseases.
