Before mineral exploitation, it is of great significance to fully understand the environmental characteristics of soil heavy metals in the mining area for the green exploitation and rational mining. The Duobuza deposit, located in Gaize County, Tibet, is one of the important deposits in the Dulong ore concentration area,and has been proved to contain 2.3444 million tons of copper resources at present. Taking the Duobuza mining area as an example, 37 soil samples were collected from four sections of the earth surface. The contents of heavy metal elements (Cu,Pb,Zn,As,Cd,Cr,Hg) and pH value were tested, and the speciation characteristics of heavy metals in 10 samples were analyzed. Single factor pollution index and Nemero comprehensive pollution index method were used to analyze the heavy metal contents, pollution index and speciation characteristics of surface soil in the Duobuza mining area. The sources of heavy metal elements and their extent of impact on the environment were also discussed. The results show that the surface soil is alkaline. Among the seven heavy metal elements, the contents of Cu in all samples are higher than the GB156181995 Ⅲ standard, only the maximum value of the Zn, Cd exceed the grade Ⅲ standard, the contents of Pb, As, Cr, Hg do not exceed the standard. The single pollution index shows Cu>Zn>As>Cd>Cr>Pb>Hg. The average value of the comprehensive pollution index is 11.60, which shows that heavy metals have a high degree of comprehensive impact on the environment. Cu mainly exists in the form of FeMn oxidation and residual state, accounting for 48.40% and 14.73%, respectively. Pb, Zn, As, Cr exists mainly in the form of residuals, accounting for 90.27%, 71.48%, 79.59% and 86.12%, respectively. Cd in the forms of FeMn oxidation and carbonatestate ,accounting for 40.05% and 22.42%,respectively.Hg in the forms of residual and humic acid state, accounting for 40.16% and 22.54%, respectively. There are three main sources of heavy metal elements: Cu, Zn, Cd, Hg derived from oxidation leaching of chalcopyrite; Pb and As derived from pyrite oxidation; Cr derived from natural weathering of rocks. Aiming at the environmental problems related to heavy metals, some suggestions were put forward for the prevention and control of heavy metals.