A wave-shaped guardrail is a movable steel guardrail composed of a combination of wave-shaped plates used at the openings of a highway median. It consists of two wave-shaped steel guardrail panels and two vertical posts fixed between them. The two posts are securely mounted between the two wave-shaped steel guardrail panels. During normal operation of the highway, the guardrail can easily be inserted into pre-set insertion holes at the opening using the removable posts, providing isolation and protection. It complements the guardrail belt along the highway's edge, maintaining uniformity and aesthetics. In the event of a collision with the vehicle, the wave-shaped steel guardrail panels, with their excellent impact resistance and energy-absorbing properties, are not easily damaged and offer excellent protection for both the vehicle and its occupants.