The invention discloses a method for sweating and preparing a wax medium for a thermostat. According to the method disclosed by the invention, an oil-soluble emulsifier and oil-soluble acid are dissolved in the sweating raw material to serve as an oil phase material on the basis of an ordinary sweating process, an inorganic salt solution serves as an aqueous phase material and is sweated after emulsification, a tiny space is formed after bubbles and salt solution produced by reaction between the oil-soluble acid and the inorganic salt are discharged, and the rapid discharge of the liquid components is facilitated; meanwhile, in the sweating process, liquid components are carried out through a wax layer by utilizing air flow, so that the solid and liquid components are forcibly separated. The method disclosed by the invention has the advantages of low production equipment investment, simple production process, low operating cost, safety, no solvent pollution and the like. The prepared product is narrow in temperature control range, can be used for a wax medium temperature control valve, and particularly serves as the wax medium for the thermostat.