The main purpose of this article is to discuss the relationship between Melancholia 1 and geometry during the Renaissance. Compared with the clear distinction between science and art today, there was no very clear boundary between science and art in the Renaissance, which made the research object of this paper have research value. The scope of investigation of this article is the work of Drer as well as other Renaissance artworks. Drer is a pioneer of the Renaissance, he is not only a representative figure of the Northern Renaissance, but also absorbed the knowledge of the Italian Renaissance, so the article chooses his famous prints for research. The main methodology is interpreting two main objects (the melancholy angle and the light from behind) in Drers Melancholia I which helps to understand the idea expressed by him, and analyzing the geometric principles used by Drer in printmaking. The main idea of Melancholia I is to express the grief that human beings cannot exhibit ideal beauty. The meaning of the melancholy angle and the beam of light is why the author makes such a prediction. The girl represents the artist, thus expressing his ideas. Speaking of the relationships, geometry provides the theory and helps with the painting. It can be seen from the layout. Drer's statement is important evidence because they reveal Drer's use of geometric theory in Melancholia I.