A 3-D laser vision measurement system with double structured-light sensors is constructed and the mathematical model of the measurement system is established. By using unknown motion of planar target,a flexible approach to easily determine all the model parameters of the measurement system in site is proposed. The real experiments show that the threedimensional coordinates RMS errors are 0. 011 rnm,0. 008 mm and 0. 115 mm in calibration case respectively. The experimental results also show that the proposed calibration method can be performed in site without special three-dimensional measurement apparatus and elaborate setup. The method advances double sensors laser vision measurement system from la boratory environments to real engineering three-dimensional metrology applications.