A prismatic AR display device, comprising: an LCOS display chip, a polarization beam splitter, PBS,, a double cemented lens, a first single lens and a beam splitting prism which are sequentially arranged along a first axis, and LCOS lighting apparatus which is arranged on a second axis perpendicular to the first axis and is close to the PBS, the double cemented lens comprises a positive lens and a negative lens, the negative lens is close to the PBS, and the positive lens is close to the first single lens; a first light incident surface of the beam splitting prism is close to the first single lens, and an optical axis of the first light incident surface coincides with an optical axis of the first single lens; an optical axis of a second light incident surface of the beam splitting prism is perpendicular to the optical axis of the first light incident surface, and the second light incident surface is opposite to a first light emergent surface; the LCOS lighting apparatus is used for illuminating the LCOS display chip, such that the LCOS display chip emits virtual image light; after being transmitted by the PBS, the virtual image light emitted by the LCOS display chip directly enters the double cemented lens, and after being refracted by the double cemented lens, the virtual image light enters the first single lens, and is refracted to the beam splitting prism by the first single lens; then, on a beam splitting surface of the beam splitting prism, the refracted light is combined with ambient light from the second light incident surface of the beam splitting prism and the combined light is transmitted to human eyes from the first light emergent surface of the beam splitting prism, wherein the virtual image light transmitted by the PBS enters the beam splitting prism after passing through five optical surfaces having certain curvature radiuses. an LCOS display chip, a polarization beam splitter, PBS,, a double cemented lens, a first single lens and a beam splitting prism which are sequentially arranged along a first axis, and LCOS lighting apparatus which is arranged on a second axis perpendicular to the first axis and is close to the PBS, the double cemented lens comprises a positive lens and a negative lens, the negative lens is close to the PBS, and the positive lens is close to the first single lens; a first light incident surface of the beam splitting prism is close to the first single lens, and an optical axis of the first light incident surface coincides with an optical axis of the first single lens; an optical axis of a second light incident surface of the beam splitting prism is perpendicular to the optical axis of the first light incident surface, and the second light incident surface is opposite to a first light emergent surface; the LCOS lighting apparatus is used for illuminating the LCOS display chip, such that the LCOS display chip emits virtual image light; after being transmitted by the PBS, the virtual image light emitted by the LCOS display chip directly enters the double cemented lens, and after being refracted by the double cemented lens, the virtual image light enters the first single lens, and is refracted to the beam splitting prism by the first single lens; then, on a beam splitting surface of the beam splitting prism, the refracted light is combined with ambient light from the second light incident surface of the beam splitting prism and the combined light is transmitted to human eyes from the first light emergent surface of the beam splitting prism, wherein the virtual image light transmitted by the PBS enters the beam splitting prism after passing through five optical surfaces having certain curvature radiuses.