The invention discloses an efficient and safe oral cavity supporting device with an automatic sterilization function. The efficient and safe oral cavity supporting device comprises a supporting device main body, atomization holes, a pressure ball, a base, a telescopic joint, an air inlet pipe, an air jetting pipe, a control valve, a connecting threaded pipe, an air bag, an atomization pipe, a nozzle, a fixed seat and a liquid storage bottle; the atomization holes are formed in the outer side of the supporting device main body; the pressure ball is installed at the tail end of the supporting device main body; and the base is arranged on the upper side of the pressure ball. The efficient and safe oral cavity supporting device with the automatic sterilization function is small and exquisite in size, simple in structure and convenient to regulate aiming at the sizes of oral cavities of different patients; after the efficient and safe oral cavity supporting device is put in the oral cavity, the supporting device main body is occluded by utilizing side surface teeth, a cavity space is not occupied basically, and no influence on oral treatment operation performed by a doctor exists basically; the supporting height can be lifted through air injection of the air bag, and treatment is convenient; and by being manufactured by adopting a non-soft silica gel material, the efficient and safe oral cavity supporting device does not damage teeth, is comfortable to occlude, also has the automatic sterilization function and is diversified in functions and convenient to use.