A beam-splitting optical module (100), comprising: a light-emitting device (101); and a diffractive optical element (103), wherein the diffractive optical element (103) is provided in a light exit path of the light-emitting device (101), and is configured to modulate incident light to project at least two groups of light beams, and can form, on a target surface (105), at least two groups of light spots, the number of groups of which corresponds to that of the light beams, wherein polarization directions of at least two groups of light beams are different, and/or optical distances from the light-emitting device (101) to the target surface (105) are different.