An embodiment of the present disclosure provides a panel structure, its manufacturing method and a projection system, which can improve optical efficiency of the projection system and reduce the volume of the projection system. The panel structure includes: a first substrate, a second substrate opposite to the first substrate, and a liquid crystal layer disposed between the first substrate and the second substrate; a reflective electrode at a side of the first substrate facing the second substrate; a transparent beam-splitting film disposed between the reflective electrode and the liquid crystal layer; and a common electrode disposed at a side of the second substrate facing the first substrate.