Position finding system with azimuth and time difference is commonly applied in electronic reconnaissance filed. In long-distance geo-location, a poor positioning accuracy would be caused by inaccurate earth model. An algorithm for azimuth and time difference joint positioning is proposed. In this method, a theoretical model of two-station azimuth and time difference joint positioning is established, and a rough analytical solution is obtained by solving the spherical triangle combining the spherical model of the earth. Then, the azimuth observation equation in the spherical coordinate system is converted into a plane equation. The earth ellipsoid model time difference measurement equation under the geocentric rectangular coordinate system is introduced. Starting from the rough solution, the exact solution is obtained based on Newton iteration method. Finally, the effectiveness of the model is verified by experimental simulation. The proposed method solving positioning finding of azimuth and time difference in long distance provides a technical reference for engineering implementation.