The present invention relates to a new crystal form of dapagliflozin, its preparation method and use thereof, specifically relates to crystalline form E of 2-chloro-5-(β-D-glucopyranose-1-yl)-4'-ethoxydiphenylmeth ane and its preparation method, and a pharmaceutical composition comprising a therapeutically effective amount of the crystal,and its use in the treatment of type II diabetes.本發明涉及達格列淨新晶型及其製備方法和用途，具體是2-氯-5-(β-D-吡喃葡萄糖-1-基)-4’-乙氧基二苯基甲烷的晶型E及其製備方法，以及含有治療有效量的該晶型的醫藥組成物和其在治療II型糖尿病中的應用。
