As the population ages, the number of patients with knee and hip osteoarthritis due to degenerative changes in old age is increasing. Severe knee and hip osteoarthritis severely affects the quality of life of patients. Joint replacement can significantly improve joint function. The quality of life of patients is greatly improved. Many patients repeatedly postpone their medical appointments for fear of intraoperative and postoperative pain. First, does it have to be painful after joint replacement? If the patient’s care team does not pay enough attention to pain, the patient does not receive systematic pain management. There is a high probability that the patient will experience more severe pain after surgery. On the contrary, if the patient’s medical team pays attention to perioperative pain control and has a series of effective analgesic measures, then the patient may have a very comfortable medical experience. Second, why does it hurt? There are many reasons for joint replacement pain, and the following reasons are common: 1. no effective multimodal analgesia 2. postoperative wound swelling 3. postoperative infection 4. inappropriate joint prosthesis type and placement location. Third, the advantages and disadvantages of pain? Postoperative pain is a double-edged sword. Pain is a protective response of the body to injurious stimuli. However, severe pain can have a series of side effects, such as inducing cardiovascular and cerebrovascular adverse events. For joint replacement surgery, severe postoperative pain can affect the patient’s postoperative functional exercise, the recovery of postoperative joint function, and the outcome of the surgery. Good postoperative analgesia is very necessary. Fourth, how to control post-operative pain after joint replacement? Post-operative pain after joint replacement is relatively heavy, and the control of this type of post-operative pain requires the collaboration of systematic surgeons and anesthesiologists. Pre-operative, intra-operative and post-operative analgesia and multi-modal analgesia are provided. Preoperatively: give patients preoperative education, have correct understanding of pain, and take appropriate amount of oral analgesics, such as COX2 inhibitors. The surgeon selects the appropriate prosthesis according to the patient’s condition and the appropriate surgical plan. The anesthesiologist gives single or continuous peripheral nerve blocks, such as femoral nerve block, lumbar plexus block, internal collecting duct block, sciatic nerve block, etc., according to the surgical site. And according to the condition, appropriate amount of adjuvant drugs such as dexamethasone are added to prolong the analgesic effect. Intraoperative: The anesthesiologist gives appropriate amount of opioid before the start of surgery, including intravenous administration and/or intravertebral administration. Giving the right amount of analgesic before the painful stimulus occurs can reduce the intensity of postoperative pain and improve the analgesic effect. Intraoperatively, the surgeon minimizes soft tissue trauma and reduces operative time, and the anesthesiologist controls the patient’s blood pressure at an appropriate stable low level to keep tourniquet pressure at a low level (230 mmHg to 260 mmHg) in a mutual effort to reduce postoperative swelling of the affected limb and tourniquet-related pain. Before the end of surgery, the surgeon injects an analgesic mixture (local anesthetic, opioid and a small amount of glucocorticoid) around the joint to reduce local inflammation and painful irritation. The anesthesiologist takes measures (perfect nerve block, adequate central analgesics, etc.) to minimize the stimulation of the pain center by peripheral tissue damage and to avoid sensitization of the pain center throughout the surgery, depending on the anesthetic modality. Postoperatively: the anesthesiologist gives the patient intravenous self-control analgesia or peripheral nerve block self-control analgesia according to the surgical site. Patients self-administered additional drugs according to their pain. The surgeon gives local cold compresses, etc., to reduce local swelling and local pain irritation. Appropriate amounts of non-steroidal anti-inflammatory drugs and central analgesics were given regularly. The surgical department and the anesthesiology department set up a special pain control team. Patients who are not satisfied with the pain control can contact the team at any time, and the team will also follow up with the patients regularly to give necessary adjuvant treatment and help. In conclusion, pain control after joint replacement is a systematic task that requires multi-point intervention, multi-modality analgesia, and good inter-departmental collaboration. A comfortable medical experience is fully achievable.