The invention relates to a manual pressure regulating device of a medical sub-hypothermia ice blanket. The ice blanket is connected with a refrigerating system via an ice blanket inlet and outlet tube, a pressure regulator is connected with the ice blanket by a tube, a manual booster pump is arranged on the pressure regulator, and a plug valve is connected to the bottom of the pressure regulator.Pressure of the inside of the ice blanket and refrigerant content can be adjusted at any time during usage according to weights and health conditions of different patients, the contact area between apatient and the ice blanket is maximized, the best contact degree is realized, the body temperature of the patient is reduced faster, and simultaneously, expectant goal can also be achieved rapidly and effectively. During surgery, due to the pressure regulating, the ice blanket cannot be broken even if the pressure is over high during usage, the ice blanket cannot excessively squeeze the body of the patient, so that influence to blood circulation of the patient is avoided, and precious time is gained for timely rescuing and treating the patient. As pressure regulation is realized by the aid of air, the manual pressure regulating device is pollution-free during working and is clean and sanitary. Besides, mechanical electric components are omitted, and accordingly the manual pressure regulating device is simple in structure and high in reliability.