Surgery II is the teaching of various theories. On the basis of mastering the basic theory of surgery, the basic concepts of surgery and the basic technical operation of surgery, students should learn and master the external scientific knowledge such as the causes, occurrence and development laws, pathology, clinical manifestations, systematic examination, key points of diagnosis, differential diagnosis, principles of prevention and treatment, surgical indications and so on of common diseases in neurosurgery, urology and orthopedics.The teaching process of surgical theories, including classroom teaching, self-study, internship and practice. The teaching content should integrate theory with practice, focus on common diseases, frequently occurring diseases and endemic diseases, implement the policy of prevention first, appropriately introduce new medical achievements at home and abroad, and pay attention to the combination of basic and clinical content. Teachers should explain deeply and thoroughly about the contents to be "mastered". Students should deeply understand their basic knowledge or basic theory in order to apply it to clinical practice. The content to be "familiar" should be explained with emphasis, and students should grasp the key points on the basis of a comprehensive understanding of the content. The content of "understanding" can be generally explained, and students have a general understanding of it. In view of the limited total class hours, it is also necessary to strengthen the cultivation of students' self-study ability. Some chapters are arranged as self-study contents, requiring students to study carefully, and teachers should give guidance and answer questions on the self-study contents.