Aluminum alloy milling cutter with adjustable length

The utility model provides a length-adjustable aluminum alloy milling cutter. The length-adjustable aluminum alloy milling cutter comprises a handle part, an aluminum alloy milling cutter head and a fastening assembly, the handle part comprises a cutter handle with a cylindrical hole and a first threaded hole, and the first threaded hole is communicated with the cylindrical hole; the aluminum alloy milling cutter head comprises a connecting part inserted into the cylindrical hole, a cutting edge part fixed to the side, away from the cutter handle, of the connecting part and three second threaded holes which penetrate through the connecting part and are formed in the radial direction at intervals, and the axial length of the connecting part is smaller than that of the cylindrical hole; one of the three second threaded holes corresponds to the first threaded hole; the fastening assembly comprises a bolt matched with the first threaded hole and the second threaded hole and a fastening nut matched with the bolt,