A blue phase liquid crystal display device includes a backlight module and a blue phase liquid crystal display panel. The backlight module includes a plurality of light sources. The light sources generate a plurality of primary color lights with different bands. The blue phase liquid crystal display panel includes a blue phase liquid crystal layer. The blue phase liquid crystal layer includes a plurality of blue phase liquid crystal molecules and a plurality of chiral dopants. The blue phase liquid crystal layer has a reflection band. The reflection band is located between the bands of two adjacent primary color lights.