The invention relates to a propelling device used in an underwater ship, in particular to an adjusting type propeller protection device. The adjusting type propeller protection device comprises a propeller and a propeller shaft; the propeller comprises propeller blades and a propeller hub; propeller blade saw teeth and saw tooth covers are arranged at leading edges of the propeller blades, whereinthe saw tooth covers cover the propeller blade saw teeth and are slidingly connected with the leading edges; and driving devices used for controlling the saw tooth covers to slide on the leading edges and stored in accommodating cavities are arranged in the hub. The adjusting type propeller protection device has the beneficial effects that entanglements can be cut through the rotation of the propeller while the rotation of the propeller is utilized because the propeller blade saw teeth are arranged at the leading edges of the propeller blades; by arranging the saw tooth covers, the normal working of the propeller can be guaranteed in the normal navigation of a ship so as to prevent the propeller from generating a lot of cavities due to irregular shapes of the propeller blade saw teeth toaffect the normal navigation of the ship; and as the driving devices are additionally arranged in the propeller hub, the saw tooth covers are controlled to extend and retract.