Provided is a projection display device for displaying a time period of one frame of stereo image as a first modulation period. The projection display device includes: a light source for emitting illumination light; a spatial light modulator for modulating the illumination light according to a plurality of frames of two-dimensional images corresponding to a stereo image to be displayed, and sequentially emitting, within the first modulation period, image light corresponding to the plurality of frames of the two-dimensional images; an angle deflection apparatus arranged in an emergent optical path of the image light and used for deflecting the image light corresponding to the plurality of frames of two-dimensional images to different angles for emission; and a projection screen for displaying the image light deflected by the angle deflection apparatus.