Based on a comprehensive analysis of S, Pb, H, O isotope geochemical characteristics of the Laochang deep porphyry molybdenum (copper) ore bodies, this paper deals with concealed porphyry metallogenic source material in Lancang of Yunnan Province. Studies show that the main sulfide δ³⁴S values of porphyry molybdenum (copper) ore bodies are between -3.99‰ and +1.8‰, concentrated in a narrow distribution area, with an average of -1.32‰. The test results of S isotope show the crust-mantle characteristics with the mixture derived from the lower crust and the upper mantle. The main lead isotope ²⁰⁶Pb/²⁰⁴Pb ratios of porphyry molybdenum (copper) ore bodies vary in the range of 17.863～18.701, with an average of 18.411. ²⁰⁷Pb/²⁰⁴Pb ratios vary in the range of 15.448～15.733, with an average of 15.628. ²⁰⁸Pb/²⁰⁴Pb ratios vary in the range of 37.753～39.104, with an average of 38.615. These data show that lead was derived not only from the formation but also from the ancient continental crust basement located in the lower part of the ore-bearing layer, deep mantle and volcanic magma. The δ¹⁸O_H2O values of porphyry molybdenum (copper) ore bodies vary between -9.51‰ and +9.41‰, δD values vary between -93‰ and -46.2‰, suggesting that the ore-forming solution of the porphyry ore body was derived from media water from magmatic water and atmospheric precipitation, with the atmospheric precipitation playing the dominant role.