The invention provides a liquid crystal display device, which comprises a first substrate, a second substrate and a liquid crystal layer sandwiched between the first substrate and the second substrate, wherein the side, facing the liquid crystal layer, of the first substrate is provided with a functional membrane layer which has a plurality of convex parts and/or concave parts and also provided with a flattened medium layer covering the functional membrane layer and a metal reflecting layer on the flattened medium layer. The functional membrane layer comprises one or more than two of a gate metal layer, a gate insulated layer, a semiconductor layer, a source-drain metal layer and an insulated protective layer. The liquid crystal display device and the manufacturing method thereof can avoid single-angle mirror reflection of a smooth plane to improve the reflectivity of diffuse reflection and expand a reflection view angle. In addition, compared with technology for improving backlight brightness, the method can ensure high visuality of a liquid crystal display used indoor and outdoor in the sun without increasing the overall power consumption of the liquid crystal display.