The CaF2 of fluorite ore, Ca and F of wall rock in Xiefang fluorite deposit have been determined systematically, and this paper analyzes the relationship between CaF2, Ca and F, which shows a good correlation, indicating that the sources of Ca and F are the wall rock of the deposit. The geothermal fluid melts the wall rock, then much Ca and F gets into the geothermal fluid, and finally, the fluorite ore is formed in the rock fracture, which is typical of hydrothermal mineralization. The value of Ca/F of the rock is bigger than that of the fluorite ore, which reveals that the Ca is superabundant during the hydrothermal mineralization, and F plays a decisive role in ore-forming.