The invention provides a naked eye 3D display part and a liquid crystal display device. By the naked eye 3D display part and the liquid crystal display device, power consumption of naked eye 3D display equipment is reduced. The naked eye 3D display part comprises a polarizer, a first substrate, a first black matrix layer, a first electrode, an optical element structure, a liquid crystal layer, a second electrode, a second substrate and a light source; the polarizer, the first substrate, the first black matrix layer, the first electrode, the optical element structure, the liquid crystal layer, the second electrode and the second substrate are successively arranged; the light source transmits collimated light to the polarizer; an opening is formed in each sub-pixel unit of the first black matrix layer; the optical element structure comprises a plurality of prisms; each prism completely covers the corresponding opening; and each prism is arranged in the liquid crystal layer. In a 3D display mode, when voltage signals are loaded for the first electrode and the second electrode, after light which enters various left-eye sub-pixel units is deflected by the prisms, the light exiting direction points to a left-eye view field, and the after light which enters various right-eye sub-pixel units is deflected by the prisms, the light exiting direction points to a right-eye view field.