Internally tangent right-angle lead angle milling device

The invention discloses an internally tangent right-angle lead angle milling device, which comprises a mainframe box and an operation table, wherein a mainframe box bottom plate is arranged at the bottom of an inner cavity of the mainframe box, an air support fixing seat is arranged at the end, close to the operation table, of the top of the mainframe box bottom plate, and an air support is arranged on the surface of the air support fixing seat; the top of the air support is connected with a gong machine fixing seat through an air support rod, a gong machine is placed on the top of the gong machine fixing seat; and meanwhile, an output shaft of the gong machine is fixedly connected with a milling cutter with a cutting edge forming a 90-degree right angle, and a plurality of base plates are arranged on the top of the operation table at equal intervals. The internally tangent right-angle lead angle milling device is provided with the mainframe box, the mainframe box bottom plate, the operation table, the air su