An anal canal pressure sore prevention fixing device comprises an anal patch with a semicircular overall appearance, an anal canal through hole is formed in the anal patch, the left side and the rightside of the anal patch are connected with a left leg inner side patch and a right leg inner side patch through connecting bands respectively, and the left leg inner side patch and the right leg innerside patch are arranged in a bilateral symmetry mode. The device is convenient to operate, The sacral tail plaster is simple in structure and good in using effect, the anus plaster, the left leg inner side plaster and the right leg inner side plaster are conveniently fixed to the anus and the inner sides of thighs of a patient, the patient feels comfortable after the plaster is pasted, pressure sores are prevented from being generated after the sacral tail plaster is pasted to the sacral tail, and an anal tube can be prevented from being bent towards one side to press surrounding skin throughthe airbag pad; The fracture notch connected with the anal tube through hole is formed in the upper portion of the anal application, the anal tube can be rapidly and conveniently arranged in the analtube through hole in a penetrating mode through the fracture notch, a patient can feel comfortable through the arrangement of the cotton cushion layer, and pressure sores caused by compression are prevented.