Pain management is an important topic that has received extensive attention from clinical practitioners. Nearly all patients with malignant tumors suffer pain at the advanced stage of their disease. Oxycodone is a first-line choice for treating moderate-to-severe cancer-related pain, and OxyContin, a controlled-release oxycodone hydrochloride tablet, is internationally recognized as a safe and effective opioid analgesic. OxyContin has the characteristics of both immediate release and sustained release, with a time to onset and peak similar to those of immediate-release morphine. It acts on both μ and κ receptors and has been shown to be effective in treating different types of pain, especially neuropathic pain, theoretically without a dose cap. However, the dose is limited in clinical applications due to various factors that are likely to affect its analgesic effect and reduce patient quality of life. Cooperation with a patient’s family members is required during the treatment of cancer pain. Chronic cancer pain has a long disease course, which could easily cause complex psychological symptoms due to their important role in the pain experience. Pain is controllable, and patients have a right to not experience pain. An optimal living state can be achieved through collaboration between physicians and patients. Rational personalized treatment of cancer pain can improve patient quality of life, relieve pain, and help prolong patient survival. This article reports the treatment procedure and adverse reactions in a patient who was treated with high-dose OxyContin, with the aim of providing a reference for other clinical practitioners.