Objective Corrosion and scaling are the main problems in the development and utilization of geothermal resources. The aim of this work was to study the scaling and corrosion rules of common metal materials in geothermal water, and to provide theoretical basis for the development and utilization of geothermal resources. Methods Scanning electron microscopy, X-ray diffraction, immersion corrosion and electrochemistry test were used to study and compare the scaling and corrosion rules of copper pipes, 304 stainless steel pipes and 20# carbon steel pipes in a simulated geothermal water environment. Results The scaling product of three kinds of metal materials was CaCO3 , but with different phases. The CaCO3 on the surface of 20# carbon steel pipes showed only calcite phase, while the CaCO3 on the surface of copper and 304 stainless steel pipes showed a small amount of aragonite phase besides calcite phase. And the 304 stainless carbon steel pipes had the minimum amount of scaling, and the distribution of CaCO3 was not as dense as that on copper. A large amount of corrosion products were formed on the surface of 20# carbon steel pipes. The inner layer was mainly Fe3 O4 , and the outer layer was Fe2 O3 . The corrosion products of copper pipes were mainly copper oxides. While no corrosion product was formed on the surface of the 304 stainless steel pipes. During the soaking, 304 stainless steel was not corroded and had the lowest corrosion current density. The corrosion resistance of the copper pipes was not as good as that of 304 stainless steel, but its pitting resistance was the best. The 20# carbon steel pipes were severely corroded and had relatively high corrosion current density. Conclusion 304 stainless steel pipes showed better corrosion resistance and anti-scaling performance than cooper pipes and 20# carbon steel pipes in a simulated geothermal water environment.