ABSTRACT Objective: To analyze effects of extracranial acupuncture therapy on sleep-related blood biomarkers, and investigate the mechanisms of extracranial acupuncture therapy for treatment-resistant insomnia. Methods: Treatment-resistant insomnia patients who visited the Sleep Therapy Clinic of Liaocheng People's Hospital, from March 1, 2023, to October 31, 2023, were selected. This study enrolled a total of 31 subjects, including 21 patients in the intervention group (with one patient excluded) and 10 healthy controls. After obtaining medical history, eligible patients were assessed using Pittsburgh sleep quality index (PSQI), Insomnia Severity Index (ISI), 24-item Hamilton Depression Rating Scale (HAMD-24), and Self-Rating Anxiety Scale (SAS), and venous blood samples were collected. Subsequently, patients received a course of extracranial acupuncture therapy lasting approximately 28 to 30 days, with the recording of changes in patient's condition. PSQI and ISI scores were recorded and blood samples were collected at the end of treatment. Patients were followed up at the first and third months after treatment, with recording of PSQI and ISI scores. The control group underwent evaluation and blood collection. Serum levels of corticotropin releasing hormone (CRH), cortisol (COR), brain derived neurotrophic factor (BDNF), S100 calcium binding protein B (S100B), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were analyzed using the enzyme-linked immunosorbent assay method. Results: The PSQI, ISI, HAMD-24, and SAS scores of treatment-resistant insomnia patients were higher than those of the healthy control group before treatment, with statistical significance. The PSQI and ISI scores of treatment-resistant insomnia patients at the end of treatment, the first month after treatment, and the third month after treatment were lower than those before treatment, with statistical significance. The levels of serum CRH, COR, S100B, IL-6, and TNF-α in treatment-resistant insomnia patients before treatment were higher than those in the healthy control group, with statistical significance, while there was no significant difference in serum BDNF levels between the two groups (P0.05). After extracranial acupuncture treatment, the levels of serum CRH and COR in treatment-resistant insomnia patients decreased compared to before treatment (P0.05), and there was no significant difference in serum BDNF, S100B, IL-6, and TNF-α levels before and after treatment (P0.05). Conclusion: Extracranial acupuncture can improve the subjective sleep scores of patients with treatment-resistant insomnia and has definite long-term effects; extracranial acupuncture improves the function of the hypothalamic-pituitary-adrenal (HPA) axis through neuro-regulation, reducing the secretion of CRH and COR to treat treatment-resistant insomnia. Keywords: Extracranial Acupuncture Treatment; Chronic Insomnia; Treatment-Resistant Insomnia; HPA Axis Fund program：Liaocheng Key R & D Program Policy Guidance Projects（2023YD37） Trial Registration: Chinese Clinical Trial Registry, ChiCTR2300069817