Under strong earthquakes, reinforced concrete (RC) shear walls at the bottom of high-rise buildings may experience an internal force state of alternating tension-shear (-bending) and compression-shear (-bending). In order to clarify the seismic and shear performance of shear walls under alternating axial tensile and compressive loads (referred to as alternating axial loads), cyclic tests on five shear-controlled large-scale RC shear walls were conducted in this study. The tests were conducted with synchronized axial loads and horizontal displacements, and a quantitative analysis of the influence of the alternating axial loads was achieved by setting two control specimens. The crack development, failure modes, load-carrying capacity, deformation capacity, and energy dissipation of the specimens were measured and analyzed. The test results indicate that different axial load cases altered the crack pattern and failure mode. With an increase in the target axial tensile load, both tension- and compression-shear capacities of the specimens under alternating axial loads decreased, with the former experiencing a more significant reduction. In comparison to the tension-shear control specimen, it was observed that the alternating axial loads significantly reduced the displacement ductility of shear walls in the tension-shear state, resulting in substantially lower energy dissipation capacity. In addition, based on the tests in this study and the collected shear wall tests, the shear strength formulas in the current codes ACI 318-19 and JGJ 3–2010, as well as a shear model previously proposed by the authors, were evaluated. Based on the test results, a reduction factor was fitted to account for the effect of alternating axial loads on the compressive-shear capacity of RC walls.