To investigate the seismic performance of prefabricated steel frame structure with ribbed thin walls, a full-scale two-story two-span structural model was designed and constructed, and shaking table tests of 12 test groups were performed. Three seismic waves, i.e., El Centro wave, Taft wave, and an artificial wave, were selected for the tests. Peak ground acceleration (PGA) increased from 0.07 g to 1.2 g gradually during the tests process. Failure characteristics, dynamic characteristics, and seismic responses of the model were studied under different working conditions. Results show that the model was in elastic state under frequent ground motion of 8 degrees, and the damage of the model mainly occurred in the ribbed thin walls, while the strain of the steel frame was low under rare ground motion of 8 degrees. With the increase of PGA, the thin walls cracked gradually, and the lateral stiffness of the model degraded gradually, while minor damage occurred in the steel frame. When PGA reached 1.2 g, the lateral stiffness of the model decreased by 37.8% in X direction and 33.6% in Y direction. During the whole tests process, the damping ratio of the model increased gradually between 4.29% and 7.19%, and the acceleration magnification factor of the model was between 0.93 and 2.46, which was obviously lower than that of traditional rigid structure. The maximum inter-story drift ratios of the model under frequent ground motion and rare ground motion of 8 degrees were 1/868 and 1/220, which meet the drift ratio limits according to the design code. The maximum inter-story drift ratio of the model under very rare ground motion of 9 degrees was 1/71, and there was no danger of collapse, indicating good seismic performance. Hence, prefabricated steel frame structure with ribbed thin walls can be applied in high seismic fortification intensity regions.