David Herbert Lawrence is one of the major writers of 20th-century English literature. His representative works include Sons and Lovers, The Rainbow, and Women in Love, which cover different fields such as novels, poems, essays, and dramas. He is known for his depiction of human emotions, sexuality, and social issues. His novel Sons and Lovers uses symbolism skillfully and intensely, in which darkness, coal mine, sunset, the moon, flowers, and so on are imagery. The use of this imagery profoundly reveals the complex emotions and feelings of the characters, thus better interpreting the various psychological activities deep inside the characters as well as the complex relationships between the characters. This paper contains two parts. The first part discusses the functions of symbolism in this novel, including four aspects: enriching the meaning, revealing the characters in depth, intensifying the emotional experience, and focusing on the theme. The second part focuses on the three aspects of the symbolism represented by the “flowers”, namely, the “flower” as a symbol of family, the “flower” as a symbol of freedom, and the “flower” as a symbol of growth and change. Through these interpretations, this study hopes to interpret the main idea of the novel in a deeper way and to enable readers to have a better understanding of the characters, the plot, the relationship between the characters, and the use of symbolism in the novel.