The invention discloses novel SGLT2 inhibitor compounds shown in a formula (I), pharmaceutically acceptable salts, easily hydrolyzed pre-drug esters or isomers and a pharmaceutical composition which contains the compounds as an inhibitor of a sodium-glucose co-transporter (SGLT). The pharmaceutical composition is used for treating or delaying related diseases such as diabetes, diabetic retinopathy, diabetic neuropathy, diabetic nephropathy, insulin resistance, hyperglycemia, hyperinsulinemia, rise of fatty acid or glycerinum, hyperlipemia, obesity, hypertriglyceridemia, X syndrome, diabetic complications, atherosclerosis, hypertension and the like. The formula is shown in the description.