The invention provides a pressing method of a monomer thermal battery. The method comprises the following steps: sequentially adding iron heating powder, cathode powder and electrolyte powder into a die; prepressing the iron heating powder, cathode powder and electrolyte powder in the die, and removing floating powder after prepressing; ensuring that the surface of an electrolyte layer is clean and smooth, without cracks, material deficiency or damage; flatly pressing an asbestos ring onto the surface of the electrolyte layer, ensuring that the asbestos ring is tightly close to the electrolytelayer, putting a cathode plate into the asbestos ring, and performing pressing formation. The method improves the forming rate and insulativity of monomer thermal batteries, and guarantees the stability and reliability of thermal batteries when the thermal batteries bear heavy load discharge.