A GLP-1 / GIP dual-targeted polypeptide, containing a first polypeptide having the following
amino acid sequence : X1X2X3GT FX4SDY SX5X6X7X8 X9X10X11X12X13 X14FX15X16W LX17X18X19, wherein X1 is Y or H, X2 is A or G or S, X3 is E or Q, X4 is I or T, X5 is I or K, X6 is A or Y or L or I, X7 is M or L, X8 is D or E, X9 is K or E, X10 is I or Q or K or E or L, X11 is H or A or R, X12 is A or Q or V, X13 is K or Q or R or H, X14 is D or E or A or L, X15 is V or I, X16 is N or E or D or Q, X17 is L or I or K or V, X18 is A or E or K, X19 is Q or G; X1~X13 do not satisfy at the same time that X1 is Y, X2 is A, X3 is E, X4 is I, X5 is I, X6 is A, X7 is M, X8 is D, X9 is K, X10 is I, X11 is H, X12 is Q, X13 is Q, X14 is D, X15 is V, X16 is N, X17 is L, X18 is A, X19 is Q. The GLP-1 / GIP dual-targeted polypeptide can effectively reduce the weight and
blood sugar level.