A structured light projection module and a three-dimensional scanning device, the structured light projection module comprising: a light source (1), a light beam shaper (2), a mask structure (3) and a projection lens (4). The light beam shaper (2) is located between the light source (1) and the mask structure (3), and the mask structure (3) is located between the light beam shaper (2) and the projection lens (4); the light beam shaper (2) is used for shaping and irradiating divergent light emitted by the light source (1) to the mask structure (3); the mask structure (3) is provided with a preset pattern and is used for modulating the shaped light beam so as to generate structured light corresponding to the preset pattern; and the projection lens (4) is used for projecting the structured light to a surface of an object to be scanned so as to perform three-dimensional scanning on the object.