Accurate positioning of magnetic source with non-vertical magnetization is an important basis for delineating the source distribution and dividing the faulted structures by using magnetic prospecting. The total magnetic anomalies are not good agreement with the distribution of geological bodies because of the influenced of magnetization direction. In order to reduce the influenced of magnetization direction, this paper derives the pseudo gradient tensor from the vertical integral of the total magnetic anomaly, and defines the mixed directional tilt gradients and analytic signal amplitudes of pseudo magnetic gradient tensor. And then we introduce a new magnetic source positioning method based on the combination of the horizontal derivatives of the mixed directional tilt gradients. Model tests indicates that the new method can effectively reflect the locations of magnetic sources with different magnetization directions, and has stronger recognition ability and positioning accuracy than the analytic signal amplitude, the total horizontal derivative of tilt gradient and the total horizontal derivative of the directional tilt gradient. When we apply the different methods to aeromagnetic data over the Tamusu uranium orefield, the new method preferably displays the trends of faults and the distributions of exposed magmatic rocks. In addition, the weak magnetic signals of Tamusu uranium orefield are extracted by the new method. Meanwhile, the results can be used to delineate the hidden rock masses, divide the concealed faults and enlarge the prospecting targets of uranium mine.