Abstract:The novel The Old Man and the Sea is a Hemingway's Spiritual autobiography as well as the description of his mental state of his late years and the epitome of his life. The writer took Santiago as the projection of his inner emotion and explored the spiritual peculiarity of a lonely old man. Through the analysis of Hemingway's life and social conditions, this paper has further interpreted the mental connotations of his loneliness and its root, and hence probe into its spiritual value for modern people.