Surface structured light 3D measurement is a typical non-contact method, with a wide range of applications in scanning measurement field. In order to quantitatively evaluate the quality and reliability of the measurement results, it is necessary to evaluate the uncertainty. Combined with the traditional error analysis method, the principle of the measurement system is explored. The uncertainty sources are analyzed by using the MSA method and the corresponding model is established. The quantitative evaluation scheme is designed for each uncertainty component, and GUM and AMCM are respectively used to evaluate the measurement uncertainty, and the results are analyzed and compared. The experiment of dimension measurement shows that the AMCM is more reliable than the GUM method. At the same time, the verification procedure shows that GUM method is still applicable when the uncertainty retains only one significant digit. However, when the uncertainty retains two significant digits, GUM method fails to be verified, indicating that it is necessary to use AMCM instead.