The invention provides a double-section type four-redundancy airplane wheel velocity sensor. A permanent magnet type sensor assembly is positioned at an inner gear ring of a casing and installed at a hole bottom of a big inside diameter hole of the casing; a dust ring, a spring and a bearing are positioned in a small inside diameter hole of the casing, and the bearing is installed at one end of the small inside diameter hole of the casing; a fluted disc of an excitation rotor assembly is installed in an inner hole of a gear ring; the end surface at one end of a magnetizer is contacted with one end surface of the gear ring, and the other end of the magnetizer is positioned at a bearing pedestal of a small bearing; a coil assembly is installed in an inner hole of the magnetizer; a magnetismisolating supporting ring is installed in a big sleeve; the big sleeve is installed in inner holes of the magnetism isolating supporting ring and the magnetism isolating bearing pedestal; and a smallsleeve is fixed at the end socket of a shaft. The double-section type four-redundancy airplane wheel velocity sensor provided by the invention is flexible in control mode, quick in response, and convenient for collection and treatment of velocity signals, brings convenience for operation of a pilot, meets requirements of different braking systems for signal collection, has wide application range,long service life, high sensitivity, excellent output characteristic, stability and reliability, and has the advantages of compact structure, convenience for dismantling, simplicity of maintenance and low manufacturing cost.