Internal corner sander

The utility model puts forward an internal corner sander. The internal corner sander comprises working plates and a handle connected with the working plates. The working plates are two square plates, and an L-shaped joint of 90 degrees is formed by the two mutually-connected working plates. The inner side surfaces disposed at the included angle of the two working plates are provided with spring clamps used for fixing sand paper. The spring clamps are disposed at edge positions of three non-connection edges on the working plates. A joint connected with the handle is arranged at the middle position of the included angle of the two working plates. The internal corner sander has following advantages: the internal corner sander is simple in structure and is convenient in assembly, disassembly and maintenance; the internal corner sander is convenient to use in that the internal corner sander can be controlled only by simple operation; the internal corner sander is high in practicality in that any angle is formed wi