The invention discloses a composite detecting impedence-based distance protection setting method. The setting calculation formula is ZDZ=Kk*Uphi1/(Iphi1+3KI01) +Kk*(I'phi1+3K'I'01)/(Iphi1+3KI01) *(Z'DZ-Z'L), wherein ZDZ refers to action impedence to be set and protected; Kk refers to a safety factor; Uphi1, Iphi1, I01, I'phi1 and I'01 respectively refer to phase voltage, phase current and zero-sequence current at a protection mounting position and phase current and zero-sequence current at a coordinate protection mounting position when the tail end of a coordinate protection line is failed; K and K' respectively refer to a zero-sequence compensation coefficient of the protection line and a zero-sequence compensation coefficient of the coordinate protection line; Z'DZ refers to action impedence of the coordinate protection; and Z'L refers to positive sequence impedance of the coordinate protection line. The method has the advantages of comprehensively considering the influence of factors such as difference of a positive sequence network and a zero sequence network and mutual induction of zero sequence on setting calculation, having reasonable setting results, optimizing protection setting and improving the comprehensive operating performance of the protection system.