With the improvement of modern quality of life, pain has become an increasing concern and is ranked by modern medicine as the fifth vital sign after respiration, body temperature, blood pressure and pulse. In contrast to acute pain, chronic pain is defined as a type of pain that persists after tissue damage has healed and lasts for more than 3 months. At the 9th International Congress of Pain Medicine held in Vienna in 1999, chronic pain was defined as a disease with a prevalence of up to 30%. Intrathecal Drud Delivery System, a special catheter is placed in the subarachnoid space of the lumbar region and a microcomputerized pump with a drug reservoir is implanted under the patient’s skin. If the input drug is morphine, it is also called a morphine pump. This method can directly act on the endorphin receptors in the spinal cord and brain with a small amount of morphine, which has a good analgesic effect and is only 1/300 of the dose needed for oral administration, while avoiding the systemic toxic side effects of large amounts of oral administration. Unlike the previous constant-rate pumps, this microcomputer-controlled morphine pump can be divided into 13 periods per day to infuse different doses of medication. Many patients with cancer pain have increased pain in the early morning or at night before going to sleep, and the split-time administration can increase the dose in addition to the base morphine amount during this time, thus achieving better pain control. Intrathecal drug infusion is one of the most advanced methods in the international pain community in recent years for the treatment of cancer pain and chronic intractable pain such as central pain and post-herpetic neuralgia. The average annual number of tumor cases in China is about 1.8 to 2 million, and about 1/4 of newly diagnosed cancer patients, 1/3 of cancer patients undergoing treatment and 3/4 of advanced cancer patients suffer from pain due to cancer, cancer-related lesions and anti-cancer treatment. Patients with cancer pain may survive for months or years, and without proper pain management, patients will suffer from pain for a long time, which greatly affects their activities, sleep, mood and overall quality of life. Without effective analgesic treatment for cancer pain, desperate cancer patients and their families may even go to extremes. For cancer pain patients with survival period over 6 months, if oral morphine drugs cannot effectively control pain or cannot tolerate side effects such as vomiting and constipation, intrathecal drug infusion system is a blessing for these patients and their families.