The invention relates to an electrothermal film and a manufacturing method thereof, belonging to the technical field of semiconductor heating. The electrothermal film is mainly prepared by adopting stannic chloride, titanium tetrachloride, stannic chloride, titanium trichloride, ferric chloride, antimony trichloride, calcium chloride, potassium chloride, cadmium chloride, stannic dioxide, stannictetroxide, hydrofluoric acid, boric acid, ethanol, isopropyl alcohol and inorganic water. By adopting the above formula, the mixture is mixed, stirred and heated to prepare into electrothermal film treating fluid, a semi-finished product of the electrothermal film is obtained by spraying the electrothermal film treating fluid at negative pressure on the electrothermal film carrier, and then silveroxide slurry is coated on the semi-finished product of the electrothermal film for baking to form a finished product of the electrothermal film. The electrothermal film has reasonable proportion andsimple manufacturing process, can be manufactured into various electrothermal film heating devices, has a working temperature capable of being up to 500 DEG C, and has wider application range. The electrothermal film of the invention also has the function of far infrared radiation, can play a role of physical therapy and health care to human body, and can help improve the quality and output of agricultural products.