Abstract: The test of the field model of the dug well foundation of bridge on the scale of 1∶2 and a mechanical analysis on the foundation soil with three dimensional finite element program is presented in this paper. The result shows that the computations of finite element is coincident with the test conclusion under the vertical eccentric load. The idea of shear compression ratio is also described. According to the theory of the interaction of stiff foundation and elastic soil, a new mechanical calculating formula of the dug well foundation of bridge under the vertical and horizontal force is proposed. At last examples for the design of engineering projects are provided.