Applying responsive design patterns in complex web applications to balance diverse user needs and system performance still faces many challenges. This paper analyzes the unique characteristics of complex web applications and their special requirements for responsive design, evaluates the actual performance of responsive design patterns in complex web applications through practical cases, and summarizes their advantages and limitations. Research has shown that responsive design patterns have significant advantages in improving user experience and application compatibility. In addition, it provides systematic theoretical support for the effective application of responsive design in complex web applications, to promote the development of this field.