Abstract: Jacking force is one of the key parameters for pipe-jacking engineering, which directly affects the determination of other parameters and the cost. Therefore, its accurate calculation is of great significance. The existing methods for the jacking force have many to be satisfied. To deal with this problem, a new method considering mud slurry thixotropy is deduced based on the analytical solution to the classic problems of an elastic half plane with a circular cavity and the flat plates model of viscous fluids mechanics. It is different from the existing methods because it takes the contact state of the pipeline and its surrounding soils as “solid to liquid”, rather than “solid to solid”. Furthermore, the new method is used in an engineering case. Compared with the existing methods, the proposed method is more reasonable, and the existing methods are relatively conservative.