A head-up display device, a head-up display method and a vehicle are provided. The head-up display device includes: a light source configured to generate a to-be-modulated light beam; a phase spatial light modulator configured to modulate a phase of the to-be-modulated light beam and emit at least two phase-modulated light beams; a reproduction component configured to perform image reproduction on the at least two phase-modulated light beams, so as to generate at least two reproduced images; at least two diffusers configured to receive and diffuse the at least two reproduced images generated by the reproduction component respectively; and a reflector assembly configured to guide the at least two light beams diffused by the at least two diffusers to a projection region, so as to form at least two projection images at different spatial positions.