The target positioning algorithm of the traditional unmanned aerial vehicle (UAV) airborne optoelectronic platform introduces a large number of angle measurement errors, resulting in low target positioning accuracy. In this paper, a hybrid nonlinear algorithm of least squares and Gauss-Newton is proposed. Firstly, the Gauss-Newton iterative nonlinear target localization algorithm based on laser ranging value is derived. Then the rough solution of linear least square is used as the initial value of the nonlinear Newton iteration method for target location estimation. The algorithm combines the advantages of the simple and easy implementation of the least squares method and the high convergence accuracy of the Gauss-Newton method, and satisfies the requirements of the Gauss-Newton method for the initial value accuracy. Experimental results of measured data show that the longitude error of fixed target positioning results of this method is less than 1.37×10-5 degrees, the latitude error is less than 6.31×10-5 degrees, and the height error is less than 1.78 meters. And the processing time of each positioning is within 6 ms, which meets the requirements of real-time positioning.