This invention refers to 17alpha ,22 - dihydroxy Furan Steride compounds and its application. The compound' s structure formula is drawing in right graph, wherein the R1, R2 and R3 = H, C1-10 direct chain, cyclane group or alkenyl , triethylsilyl, dimethyl- tert-butylsilyl-biphenyl-tert-butylsilyl, methoxymethyl or tetrahydropyranyl. R4 = H see right formula a, b, C1-10 direct chain, cyclane group, alkenyl or alkynyl , R5 = C1-10 direct chain or cyclane group, R6 = H, C1-10 direct chain or cyclane group or alkenyl, triethylsilyl, dimethyl- tert-butylsilyl, biphenyl-tert-butylsilyl, methoxymethyl, tetrahydropyranyl. The start materials is diosgenin, which is easy available and cheap. Through F-cyclic degrading, the degradation product' s structure is converted into 17alpha,22 - dihydroxy furan steride compound. The compound again with F-cyclic restructure becomes the sapogenin, which is medicinal value. The process thereof is simple, adapted for industrialized production. It's glycoside of medicinal herbs Chonglou (Paris petiolata bak) sapogenin as one active ingredient, whose synthesis is provided herewith is effectively.