Multiple Inverse Method is useful for separating stresses from heterogeneous faultslip data. By using the method applied to fault slip data in the Yongping Copper Deposit, three phases of palaeotectonic stress were found since the Indosinian. At first, EW direction of compressive stress field formed SN direction of folds, faults and interlayer fracture zone. Then the tectonic stress field transformed as NWSE direction. Accompanied by the intrusion of pluton, thermal metamorphism occurred on interlayer fracture zone.Hydrochloride rock changed into skarn and mineralization. At last, EW direction of compressive stress leads to increasing nappe distance.As a result, migmatite and skarn thrust over Paleozoic strata from east to west.