The error propagation model in structured light system was presented.Based on Taylor decomposition and the principal of matrix turbulence,the measuring error of structured light and error from light-plane calibration were analyzed,in which cross-ratio invariant was used in calibration of structured light system.The demands of precision in the specific example were presented,which were ones of calibration parameters and samples under the conditions of acquisition of ±0.5 mm precision in the measuring range of 1 000 mm.According to the error propagation,experiment was made by using the precision of calibration samples.The measuring results are that the value of Root Mean Square(RMS) is 0.333 4 mm,which meets the requirements of theoretical precision.The experimental results validate that those error analyses would provide the principle basis for wider application of structured light system.