A method for manufacturing a reflective coding plate is provided. The method includes steps of providing a first substrate, forming a mixture layer on the first substrate, providing a second substrate on the mixture layer and thereby a sandwich structure is formed, performing an orientation process on the sandwich structure, providing a mask having a code pattern thereon on one side of the sandwich structure, exposing the side of the sandwich structure to a UV light, removing the second substrate, and removing an unreacted part of the mixture layer.