The theory of absurdity of sartre and camus is an important legacy in the field of philosophy and literature in the 20th century. It puts forward a profound reflection on reality, rationality and the meaning of existence. His theory of absurdity mainly focused on the nature of existence and the way humans exist. He believed that the real world was absurd and that the existence of human beings was meaningless because all our actions and decisions were based on reason and logic, but in the end, they would appear in an absurd way. Therefore, he proposed the idea that existence is absurdity, that is, human existence is based on absurdity, and we must learn to find meaning and purpose in absurd reality. Camus's theory of absurdity emphasized human resistance and exploration of absurdity. He believes that the absurd reality is the premise of human existence, we must face and accept it, but we can go beyond the absurd and find the true meaning and value through resistance and exploration. Camus's theory of absurdity mainly involved the concepts of "absurdism" and "rebellion". He believed that the existence of human beings was meaningless, but we must learn to find our own meaning and value in absurdity. The absurd theory of Sartre and Camus explored the essence and significance of human existence and proposed a profound reflection on reality and rationality. These thoughts had a profound influence on the literature and philosophy of the 20th century, and also provided important enlightenment for the later absurd literature and philosophy.