A liquid crystal display device and its display panel are provided. The display panel includes a first substrate, a second substrate, a PDLC layer and a plurality of gridwall structures. The first substrate and the second substrate are opposite to each other. The PDLC layer and the plurality of gridwall structures are located between the first substrate and the second substrate. The plurality of gridwall structures are spaced from each other and disposed in the PDLC layer. Each gridwall structure includes a transparent gridwall and a film structure covering the surface of the transparent gridwall. The refractivity of any two adjacent film layers of the first to Nth are different, and the reflectivity of one surface of the film structure facing the transparent gridwall is higher than the reflectivity of one surface of the film structure facing away from the transparent gridwall.