Abstract: The location of the node is the basis in the application of WSN. In order to improve the precision of the location, making use of the constraint relation between transfer matrix and observation matrix, the constrained total least square algorithm based on TDOA are applied. In this dissertation, this location algorithm is transformed into the criteria total least square algorithm issue, then, the criteria total least square algorithm is equaled to the non criteria total least square algorithm. Finally, target location can be estimated by Newton iterative and the computer simulation demonstrates its performance.