The invention provides an inflatable waist protecting belt structure which comprises an inner inflatable belt body and an outer fixed belt body. An inflatable space is formed inside the inner inflatable belt body, an inflation valve is arranged at the position adjacent to one end of the outer side of the inner inflatable belt body so that an air delivery valve of an inflator can execute an air inflation action to the inflatable space, and a penetrating hole is formed in the position adjacent to one end of the inner inflatable belt body. The outer fixed belt body is smaller than the inner inflatable belt body in width and is movably located at the position adjacent to a transverse middle section of the outer side of the inner inflatable belt body in a surrounding mode, one end of the outer fixed belt body penetrates the penetrating hole of the inner inflatable belt body and extends to the inner side of the inner inflatable belt body, a fixing ring is fixed on the outer fixed belt body, and the other end of the outer fixed belt body can penetrate the fixing ring and tie up the inner inflatable belt body after being tightened. The elder, patients and users with small strength can easily tie up the inflatable waist protecting belt.
