Abstract: Due to the characteristics of unconditionally stable, good algorithm damping properties, no transcendental phenomenon, and of truncation error, the high order single-step method had been successfully applied in nonlinear seismic response analysis and vibration controls. Based on the characteristics of the pseudo-dynamic testing and taking into account the permissible system accuracy, this paper introduces the concept of equivalent shear stiffness, and proposes the high order single-step algorithm of pseudo-dynamic testing. The feasibility and advantages of this algorithm are demonstrated by a comparison between numerical simulation results of the SDOF and 2 DOF structure with those of the three-level full-scale testing.