A protective cover comprises a fixing plate, a first folding plate, a second folding plate, and a third folding plate. The fixing plate is fixed connected to a back surface of an electronic device and includes a first magnetic component. The first folding plate is foldably connected to the fixing plate and attaches to the back surface by a first attaching force. The second folding plate is foldably connected to the fixing plate and attaches to the back surface by a second attaching force. The third folding plate is foldably connected to the second folding plate and includes a second magnetic component to attach to the back surface. When the protective cover is folded, the third folding plate, the second folding plate, and the first folding plate leave the back surface in sequence; the fixing plate, the first folding plate, and the second folding plate form a support state.