Abstract: In order to investigate the mechanical properties of steel tie rods under different loading conditions, the monotonic tension and low-cycle reciprocating tension and compression experiment was carried out on ten GLG650 steel tie rod specimens. The load-displacement curves, yield bearing capacity, maximum bearing capacity and ultimate bearing capacity of the steel tie rods and corresponding deformation and failure modes were obtained. The results of experiment and analysis show that the load-displacement curve of the steel tie rod is close to a straight line in the yield strengthening stage, and the load-displacement curves of the steel tie rods with smaller slenderness exhibit cyclic softening phenomenon under reciprocating tension and compression. After yielding in tension, as the axial deformation of the steel tie rod increases, its lateral deflection increases with the reverse compression, and the middle part of the rod enters into yield under compression and bending. The elongation after fracture of the steel tie rods is about 3.4% to 6.8%, which is much smaller than the elongation at breakage of the steel sample. Though the fracture mostly occurs at the loading end or fixed end, the fracture in the middle of the bar increases when the slenderness ratio is small, due to plastic damage accumulation under compression and bending. The load-displacement hysteresis rule of the steel tie rod determined according to the characteristic points can be used for elastic-plastic analysis under reciprocating load.