The preface of graduation thesis is the preface of the whole thesis, and it is an important part to show readers the research theme, purpose and significance. The following are the steps to write the preface of graduation thesis:

1. Determine the purpose of writing. Before writing the preface, we should determine the purpose and significance of writing, clearly introduce the research background, purpose and importance, and pave the way for the follow-up research content.

2. Introduce the research background. In the preface, it is necessary to introduce the research background, explain the reasons for choosing the topic and the background information of the research, so that readers can better understand the significance and value of the research.

3. Explain the purpose and significance of the research. In the preface, we should clearly explain the purpose and significance of the research, and explain the value and contribution of the research, so that readers can better understand the importance and significance of the research.

4. Summarize the structure of the paper. In the preface, it is necessary to summarize the structure and content of the paper, explain the main contents and research methods of each chapter, and let readers have an overall understanding of the whole paper.

5. Pay attention to language expression. In the preface, we need to pay attention to the refinement and accuracy of the language and avoid using too complicated or vague language expressions, so that readers can clearly understand the research content and significance.

In short, the writing of the preface of graduation thesis needs to pay attention to the refinement and accuracy of the overall structure and language expression, so that readers can clearly understand the background, purpose and significance of the research.