In order to avoid large amounts of computation with the elastic compensation method, the incremental elastic finite element iterative method(IEFEIM)is proposed for solution of the ultimate load of complex structures, based on the advantages of elastic-plastic analysis and plastic limit analysis. With the load factor β as a variable, and by using the self-adaptive increment adjustment technique, the maximum load factor β_max satisfying the equilibrium and yield conditions is obtained by iteration and approximation. In contrast to the elastic-plastic analysis method, the IEFEIM only requires the strength criterion of materials and does not require the constitutive relationship of materials after yielding and failure; in contrast to the plastic limit analysis method, the IEFEIM obtains the maximum load factor by directional search and approximation, without using the programming algorithm for large-scale search; and in contrast to the elastic compensation method, the IEFEIM generates the global stiffness matrix for only one time, without any need of generating the global stiffness matrix for each step, effectively decreasing the amount of computation in iterations. Practical application in engineering projects shows that the IEFEIM can obtain the ultimate load of high dams effectively and provide the structural characteristics close to the ultimate state.