In this paper, a selflocation method is proposed. Constrained by the coordinates of control points, the parameters of selflocation are solved by LevenbergMarquardt algorithm which is a nonlinear least square method. Taking the example of double transmitters, the solution model of the selflocation method is introduced in detail. By the experiment, it is verified that the selflocation method is feasible, the solution model is effective and the accuracy of selflocation can meet the requirements of engineering survey.