Brand packaging design is an important field in graphic design. With the growth of technology, computer aided design (CAD) has become a key tool in the process of brand packaging design. This article aims to explore how to integrate CAD-aided design into brand packaging design in graphic design teaching, improve students' design ability and efficiency, and cultivate innovative thinking and practical ability. Through the design and test of packaging image processing algorithm, the contrast, brightness and color balance of packaging image are adjusted, and the clarity and vividness of the image are improved. Through the design and test of packaging image processing algorithm, the effectiveness and superiority of the algorithm are proved. Simulation results show that this algorithm improves the classification performance and the accuracy of brand pattern integrity detection on the basis of retaining the main information. Moreover, the image processing method of the algorithm takes less time and shows higher running efficiency. This algorithm can not only improve the effect and quality of brand packaging design, but also reduce the design cost and time. In the future, more emerging CAD technologies can be introduced into graphic design teaching to meet the needs of industry development.