Abstract: Due to the problem of complexity and high-cost character of dynamic analysis in the processing of structural dynamic optimization, and infeasibility to direct dynamic optimization, a transformation method of equivalent static loads from dynamic loads based on volume potential energy was proposed. Analyzed the constitutive equation of volume potential energy, the most dangerous time points of the structure dynamic response were found by the critical time points identification method for solution space of global dynamic stress based spectral element interpolation. A mathematical model for the transformation method of equivalent static loads was constructed and it was solved by Direct algorithm. Last, 10 bar truss, 124-member plane truss and 1-bay 2-storey frame were taken as examples to verify the feasibility and validity of the proposed method. Results show that the displacement used proposed method is more realistic than the literature displacement of 6.74%, 4.57%, 8.5%, indicating that the proposed method is feasible and effective, and lay a foundation for the structural dynamic response optimization.