With inner mechanisms,the solution of kinematically indeterminate systems is much more complicated than that of kinematically determinate systems.To understand the structural behaviour fully,the compatible and incompatible equilibrium equations of kinematically indeterminate systems had been derived and solved detailedly in this paper.Considering the solution of kinematically indeterminate system involves large displacement,the deformation compatible equations based on small distortion were re-derived and the equations which based on large distortion were adopted.Numerical results show the proposed method is accurate and efficient,and can be used to determine the equilibrium state of kinematically indeterminate systems.