In the field of digital communication, Matlab is widely used for system design and simulation. This article explores the Matlab design and simulation of digital communication systems, with a focus on the relevant topics of undergraduate graduation thesis. Through the Matlab tool, we can systematically design and simulate various aspects of digital communication systems, including signal processing, modulation-demodulation, and key parameters such as error rate. This provides powerful tool support for the research of undergraduate theses. In the undergraduate thesis, we will delve into the Matlab design process of digital communication systems, analyze simulation results, and evaluate system performance. Through Matlab simulation, we can gain a more comprehensive understanding of the working principles of digital communication systems, providing strong support for solving practical problems. This article will conduct in-depth research on the Matlab design and simulation of digital communication systems, providing practical references for undergraduate theses in related fields.