The Huachangshan lead-zinc deposit in Yunnan is a typical MVT lead-zinc deposit formed in the fold-thrust belt, with most of the ore bodies located along and on both sides of the faults. In this study, four sets of faults with different occurrences were identified by cataloguing adits, three of which have developed hydrothermal fluids that include a non-mineralized fluid, a copper-silver fluid, and a lead-zinc fluid. All of them develop hydrothermal calcite during the hydrothermal process. As a result of in-situ rare earth element (REE) analysis, it is concluded that calcites originated from hydrothermal fluids unrelated to magmatism. In addition, calcites display different REE distribution patterns, and different positions on lg(Y/Ho)-lg(La/Ho) and Yb/Ca-Yb/La (atomic ratios) coordinate diagrams. These data indicate that the three fluid sources are different or that they have been modified from cogenetic fluid. The carbon and oxygen isotopic values of the calcites indicate a tendency for dissolution and reprecipitation of marine carbonate rocks within the basin. The oxygen isotopic characteristics of calcites indicate that the three fluids originated from basin brines and lead-zinc fluid mixed with meteoric water. Based on the detailed analysis of the fault activities and hydrothermal fluid characteristics, it is considered that the tensile faults after regional thrust fault are the main ore-controlling faults in the Huachangshan lead-zinc deposit.