Thermal simulation experiments on thermochemical sulfate reduction system of natural gas and magnesium sulphate were carried out using an autoclave in the presence of water. The products were characterized by some advanced analytical methods. Thermodynamics and reaction kinetics of thermochemical sulfate reduction processes had been investigated on the basis of the experimental data. The results showed that thermochemical sulfate reduction of natural gas with magnesium sulphate could proceed at 425 degrees C-525 degrees C to produce magnesium oxide, carbon, hydrogen sulfide, and carbon dioxide as the main products. The reactions are thermochemically possible and high temperature is favored. Long-chain hydrocarbons more easily thermodynamically participate in the reactions than short-chain hydrocarbons. According to the reaction model, the calculated activation energy for the reaction between natural gas and magnesium sulfate is about 78.975 kJ/mol.