The preface of the graduation thesis of undergraduate computer major can include introduction, objectives and research questions, research methods and methodology, and structural overview.

1. Introduction: Introduce the research topic and purpose of the paper directly. Talk about the reasons for choosing this topic and why it is important for individuals and academic fields. You can mention the background information of the current field to arouse readers' interest.

2. Objectives and research problems: define the research objectives and specific problems to be solved. This paper expounds the core issues concerned by the research, and explains how the research will fill the gaps in existing knowledge or improve existing methods.

3. Research methods and methodology: Briefly describe the methods and methodology adopted in the research. Explain the rationality and applicability of the selected research method, and explain how this method can help answer research questions and achieve research goals.

4. Structure overview: summarize the structure of the whole paper and the content arrangement of each chapter. Briefly introduce the main contents of each chapter, so that readers have a clear understanding of the organizational structure of the whole paper.

When writing the preface, make sure that the language is concise, clear and focused. The preface should arouse readers' interest and clearly indicate the research objectives and methods.