The invention provides an inflatable and expandable three-dimensional truss on-track maintainable solar panel. In the case of on-track motion of the solar panel, an astronaut needs to walk in space environment to integrally replace the solar panel which needs to be replaced, which causes threat to life safety of the astronaut. An inflatable and expandable three-dimensional truss is composed of a plurality of inflatable and expandable three-dimensional truss units which are in sequential end-to-end communication, and the head and tail ends of the inflatable and expandable three-dimensional truss are fixedly connected with a triangular supporting plate; an adjacent side plane between each inflatable and expandable three-dimensional truss unit and two guide tubes is internally equipped with a solar cell substrate which is connected with a main supporting tube, and the solar cell substrate is composed of a cell thin sheet, a supporting structure board and a plurality of first magnet exciting coils; the cell thin sheet is supported by the supporting structure board, and the supporting structure board is fixedly equipped with the first magnet exciting coils; and the cell thin sheet is attracted with the supporting structure board together by means of a magnetic force, and a capture board is arranged outside the solar cell substrate. The solar panel of the invention is used in a manned spacecraft such as a space station and the like.