In order to study the effect of temperature on underground water solution erosion feldspar, the paper applied groundwater chemical simulation software phreeqc to simulate the water chemistry relationship between solubility and temperature under different CO2 partial pressure at the two situations that calcium feldspar, potash feldspar, sodium feldspar exist in solution at the same time or respectively. The simulation results show that the three kinds of feldspar present in solution at the same time.The solubility of calcium feldspar, potassium feldspar is far less than that of individual existence.The solubility of sodium feldspar is far more than that of calcium feldspar and potash feldspar. The solubility of sodium feldspar increases with the rise of temperature quickly; the solubility of three kinds of feldspar increases with the rise of temperature at the existence of three kinds of feldspar in solution respectively. At the respective existence of three kinds of feldspar, the higher the tempreture of groundwater solution and content of CO2, the stronger the erodent capacity of three kinds of feldspar; the rise of temperature can drop the erodent capacity of three kinds of feldspar to groundwater solution in the situation that the three kinds of feldspar is present in the solution and can still enhance the erodent capacity of sodium feldspar .