The invention relates to the field of data acquisition, in particular to a three-dimensional scanning system for an object surface shape. The three-dimensional scanning system comprises multiple groups of monochromatic light scanning devices which surround a center and are used for scanning the three-dimensional shape of an object in the center, wherein each group of monochromatic light scanning devices can only emit and receive monochromatic light in the same wavelength range, and the wavelength ranges of the monochromatic light emitted and received by adjacent monochromatic light scanning devices are not overlapped. According to the three-dimensional scanning system for the object surface shape, the multiple groups of monochromatic light scanning devices can work simultaneously without mutual interference and acquire surface shape images of all parts of the object synchronously, so that the detection time is shortened greatly, the probability of great change of the outer shape of an moving object in a detection process is reduced effectively, the consistency and coherence of the acquired images are improved, and the image splicing difficulty is reduced.