A multi-stage solar power device includes a light-permeable base plate, a plurality of light-condensing plates, a heat-conducting tube, at least one gas turbine, a gas inlet tube and a gas outlet tube. The light-condensing plates include a plurality of arcs with different length. The light-condensing plates are spaced from each other and arranged under the light-permeable base plate to define a plurality of light-reflecting chambers. The heat-conducting tube has first and second ends and extends through the light-reflecting chambers. At least one gas turbine is disposed in the heat-conducting tube. The gas inlet tube has first and second sections. The first section protrudes from the light-permeable base plate, and the second section extends through the light-permeable base plate. The gas outlet tube has one end protruding from the light-permeable base plate, as well as an other end extending through the light-permeable base plate.