College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China

With the development of gravity gradient full tensor measurement technique, three-dimensional (3D) inversion based on gravity gradient tensor can provide more accurate information. But the forward calculation of 3D full tensor sensitivity matrix is very time-consuming, which restricts its development and application. According to the symmetry of the kernel function, the authors reconstruct the underground source of geological body to avoid repeat computation of the same value, and work out the corresponding relationship between the response of geological body to the observation point and the response of reconstructed geological body to the observation point. According to the relationship, rapid calculation of full tensor gravity sensitivity matrix can be achieved. The model calculation shows that this method can increase the speed of 30-45 times compared with the traditional calculation method. The sensitivity matrix is applied to the multi-component inversion of gravity gradient. The application of this method on the measured data provides the basis for the promotion of the method.