The invention discloses a composite skull base repair fixer. The top end of a connecting rod is provided with a fixed disc, the lower end of the connecting rod is provided with a movable disc capable of moving on the connecting rod, the fixed disc and the movable disc are coaxial on the connecting rod and use one side, opposite to the movable disc, of the fixed disc as the inner side, a biological dura mater matched with the shape of the fixed disc is pasted on the inner side surface of the fixed disc, a silica gel bag filled with water absorption resin is additionally arranged on the connecting rod arranged between the fixed disc and the movable disc, a plurality of through holes are uniformly formed in the movable disc, the inner side surface of the movable disc comprises an inner ring and an outer ring, the through holes are formed between the inner ring and the outer ring, the inner ring is butted against and in contact with the silica gel bag, a plurality of needle-shaped sawteeth are arranged at the outer ring, the needle-shaped sawteeth face the silica gel bag, in addition, a flow guide groove is formed in the needle-shaped sawteeth, when the silica gel bag is pierced by the needle-shaped sawteeth, one end of the flow guide groove is communicated with the silica gel bag, and the other end of the flow guide groove is communicated with a bone window gap of the skull of a patient. The composite skull base repair fixer has the advantages that the biological dura mater capable of being trimmed and the water absorption resin of the silica gel bag with good conformity can be applicable to the complete repair on various defective bone windows, the leakage of cerebrospinal fluid can be repaired, and the death rate and the occurrence rate of postoperative intracranial infection are reduced.