Abstract: The adsorption sites and mechanism of H atom on α-Zr(0001) surface were calculated and analyzed from microstructure, adsorption probability, adsorption energy, Mulliken charge population and density of state, and etc. based on the integration of Monte Carlo (MC) simulation and first-principle density functional theory (DFT) method. The results indicated that the H atom firstly generated physical adsorption on the Zr(0001) surface and then changes to chemical adsorption. The charge continuously transferred from the surface Zr(0001) atoms to the H atom throughout the entire process, and finally stabilized. Furthermore, the H atom directly bonded with the most surface Zr(0001) atoms after stable adsorption, and the major contribution of Zr-H bond was made by partial density of state of H(s), Zr(s) and Zr(d) orbitals. Comprehensive analysis shows that the priority order of the adsorption sites of H atoms on the Zr(0001) surface is hexagonal close packed gap (hcp)> face centered cubic gap (fcc)>bridge, and the top site is the impossible adsorption site.