Cancer pain is the most prevalent symptom experienced by cancer patients. It substantially impacts a patient's long-term physical and emotional health, making it a pressing issue that must be addressed. Purinergic receptor P2X7 (P2X7R) is a widely distributed and potent non-selective ATP-gated ion channel that regulates tumor proliferation, chronic pain, and the formation of inflammatory lesions in the central nervous system. P2X7R plays an essential role in cancer pain and complications related to cancer pain including depression and opioid tolerance. This review focuses on the structure and distribution of P2X7R, its role in diverse tissues in cancer pain, and the application of P2X7R antagonists in the treatment of cancer pain to propose new ideas for cancer pain management.