In order to promote the application of Q500GJ high-strength steel in steel structure engineering, five specimens of Q500GJ high-strength steel welded H-section columns were tested under horizontal reciprocating loading. The effects of slenderness ratio and loading conditions around the strong or weak axis on the failure mode, deformation capacity and seismic energy dissipation capacity of specimens were studied. The results show that the load-displacement hysteretic curves of all specimens are rich and the hysteretic performance is good. The skeleton curves are basically symmetrical in both the right and reverse direction with similar trend . From elastic deformation to yield point, after reaching the maximum load, the skeleton curves begin to decline until the plastic failure. The specimens under cyclic loading around the strong axis fail due to local elastic-plastic instability of the plate, and the plasticity develops insufficiently. While the specimens under cyclic loading around weak axis fail due to the whole section into plasticity. The ductility coefficient of specimens under cyclic loading around weak axis is much higher than that under cyclic loading around strong axis. The maximum and minimum inter-story displacement deflection of the specimens are 1/20 and 1/26, respectively, which meet the limit requirements, i.e., 1/50 of elastic-plastic inter-story displacement deflection, for multi-story and high-rise steel structures in GB 50011-2010 Code for Seismic Design of Buildings.