I. Overview The traditional view is that postoperative pain is normal and inevitable, and we can often see a series of side effects caused by pain in the clinic, especially in patients after knee replacement. Traditional analgesic protocols are single and unsystematic, with poor results. At present, more and more attention is paid to perioperative pain control at home and abroad, and a diversified pain management concept with preoperative patient education, over-the-top analgesia, multimodal analgesia and individualized analgesia as the main contents has been formed. The purpose of “pain-free ward” is to standardize the management of pain and minimize the side effects of pain on patients. Through the joint efforts of medical and nursing staff and patients in our department for many years, the Department of Orthopedics of Friendship Hospital has established a perfect working model of pain-free ward, which has greatly relieved the pain of patients in the perioperative period. III. Strategies for perioperative analgesia of artificial knee 1. Preoperative education and assessment of pain The primary issue of management is to change the concept and pay attention to education. Pain education targets include patients and family members to change their misconceptions about pain, establish a pain-free concept, and improve compliance. Active patient participation is the key to good analgesia. The assessment methods of pain are simple, and visual analog scoring (VAS) and numerical grading method (VNRS) are commonly used in clinical practice. 2. Over-the-top analgesia Over-the-top analgesia means that analgesic drugs are given before the occurrence of injurious stimuli (such as surgery) to reduce the sensitivity of the pain center to painful stimuli, so as to achieve the effect of reducing pain after injury. Once the central nerve produces a hypersensitivity response to pain, pain control will be difficult. 3.Multimodal analgesia Multimodal analgesia is proposed to reduce the amount of opioids, and the application mode includes anesthesia at the spinal level, peripheral nerve block, opioid and non-opioid application. This model greatly reduces the side effects and the amount of opioids caused by the application of a single analgesic drug. At present, a large number of clinical trials have verified the effectiveness of multimodal analgesia. 4.Individualized analgesia Individualized analgesia is proposed with the gradual development of medical research, because different patients have different reactions to pain, and the program requires that the analgesic program, drug dose, route of administration and time of administration vary from person to person, aiming to achieve the best analgesic effect by applying the least amount of analgesic drugs.