Abstract: It is very difficult to solve the internal forces of statically indeterminate structures under local distributed load by directly using the force method or displacement method. This paper uses the integral method to derive the load constants under local uniformly distributed loads and local triangular distributed loads using the load constants under a single concentrated load, thus solving the problem of directly using the displacement method to solve the internal forces of statically indeterminate structures under local distributed loads. The derivation of load constant under local distributed load by integral method is more clever and easy to understand than the force method, the virtual beam method and the energy principle, which can deepen students' understanding of the displacement method and the load constants, broaden students' thinking ability, and has certain teaching practical significance.