The coupling test combining marine atmospheric environment and tensile/compressive loading was conducted on 30CrMnSiNi2A high-strength steel using a self-developed test device. For comparison, static exposure tests were performed in WanNing. The corrosion behavior of the steel was evaluated in terms of corrosion morphology, mechanical properties, and fracture morphology. Results indicate that the corrosion forms of 30CrMnSiNi2A steel in the two tests were essentially identical. Nevertheless, the coupled environment-load test accelerated the corrosion development of the steel, and the mechanical degradation in the coupling test was greater than those in the static exposure test. Furthermore, the coupling test effectively replicated the corrosion fatigue behavior of aircraft landing gear struts during its service life, providing a reliable method for assessing material adaptability under the coupled natural environment and working load.