A preparation method of an LCoS panel provides a wafer substrate at a wafer level, the substrate including die areas with active circuits. A seal is formed on the wafer substrate, coupling to a transparent substrate. Vias extend through a thick silicon substrate and there are conductive interfaces on the second surface in each die area, the active circuit being connected to the back side of the wafer substrate by the vias and the conductive interfaces. The wafer substrate and the transparent substrate are cut to obtain LCoS panels. These processes (especially the circuit packaging) are all performed at wafer level, improving production efficiency and reducing production cost. An LCoS panel so prepared is also disclosed.