A projection apparatus, a display device, and a vehicle. The projection apparatus comprises a lighting unit (110), a polarization beam-splitting unit (120), a light modulation unit (130), a convergence unit (140), and a projection unit (150), wherein the lighting unit (110) is used for providing a first light beam; the polarization beam-splitting unit (120) is used for performing polarization beam-splitting on the first light beam, and outputting a second light beam obtained by means of polarization beam-splitting; the convergence unit (140) is used for converging the second light beam, and guiding the converged second light beam to the light modulation unit (130); the light modulation unit (130) is used for performing light modulation on the converged second light beam, so as to obtain a third light beam; and the projection unit (150) is used for projecting the third light beam.