Abstract: Slip Lines Method (SLM) has strict bases both on mathematics and mechanics. Using finite difference algorithm with dense mesh , the numerical solution approaches to that of the static limit equilibrium analysus , and accurate value can be obtained. According to a vast amount of computations and analyses , the inherent link between N γ and dimensionless parameter λ=γ·B/(c+q·tanφ) is brought out for the first time, then the SLM accurate numerical solution can be fitted to a concise analytic formula. The bearing capacity formulae proposed in this paper take the nonlinearity of N γ into account for the first time, and avoid the superposition error . By means of comparison with various classic bearing capacity formulae and model test results, the validity and utility of the bearing capacity formulae proposed in this paper are examined. Now the bearing capacity formulae have been recommended to the revised edition of Port Engineering Technical Codes.