This article presents the clinical experience of Chief Physician Li Zhaohui in treating moderate-to-severe cancer pain with acupuncture based on the traditional Chinese medicine theory of "Xi-cleft points being indicated for acute pain." Dr. Li believes that the core pathogenesis of cancer pain lies in "meridian obstruction, qi and blood stasis, and phlegm-turbidity coagulation," and its acute and intense characteristics align well with the theory that "Xi-cleft points are indicated for acute pain." He advocates for an acupuncture approach that combines "local point selection" with "meridian-based point selection," and employs the combination of Xi-cleft and front-mu points to maximize the alleviation of cancer-related pain. In acupuncture practice, he emphasizes specific needling techniques, such as "heat-producing needling" and "cool-producing needling," to regulate cold and heat patterns. This article systematically elaborates on his syndrome differentiation approach, point selection principles, and characteristic techniques, supported by typical medical cases, aiming to provide effective references for the traditional Chinese medicine treatment of cancer pain.