In order to realize the geometric measurement of large scale workpiece,a measuring net for multiple measurement stations was established.With the aim of the information fusion of multiple measurement station,a relevant multi-sensor information fusion method was researched.The spatial data of multiple measurement stations were registrated based on singular value decomposition to unify as global coordinate system.Then,the measuring model of each measurement station was established to get its covariance matrix and Jacobian matrix,so the weight matrix was obtained by the optimum fusion criterion of matrix weighting linearity minimum variance for fusing effectively measured data of multiple measurement station.A simulation experiment was carried out and the average measuring results were given as follow,the measurement errors of total station,theodolite and laser tracker are 0.745 1 mm,0.044 9 mm and 0.032 7 mm,respectively,and the fusion measurement error is 0.012 8 mm.Finally,the fusion method was applied to measure a net in tunnel component.The validity of fusion criterion for precision is proved by theory,simulation and practical experiments,and the fusion precision is superior to each partial precision.