Abstract: A pseudo-dynamic test is carried out to study the seismic performance of the T steel semi-rigid connection steel frame under two kinds of earthquake peak acceleration, and the peak strain, the displacement and the load variation of the T steel connection steel frame with and without the vertical load are analyzed and compared, together with the load-displacement hysteresis curves. Experimental results show that the T steel semi-rigid connection steel frame enjoys better deformation capacity and ductility performance, and the hysteretic performance is good, that explains the good seismic performance.The dynamic response is increased with the increase of the earthquake load; the vertical load has a great effect on the displacement response, but has little effect on the strain and the interlayer load for the semi-rigid connection steel frame.