Abstract: Based on the spring-center method of a curved-girder-finite-segment-element method, the flexibility matrix is deduced, but it is difficult to solve its inverse matrix directly and get an analytical solution of a stiffness matrix because each element is very complex. The numerical method is used to solve an inverse matrix in related documents and finite element program usually. In this paper, a method of matrix inversion is proposed and verified, and the concrete expression of the stiffness matrix is gotten according to the method of matrix inversion, and the improvement of a curved-girder-finite-segment-element method is proposed. The example and comparison indicate the method and formulas are correct and reliable. On the basis of the new method and analytical solution of the stiffness matrix, the program of the curved-girder -finite-segment-element method is simplified greatly, and efficiency and accuracy of a computer are improved.