Background and Aims The success of thyroid surgery largely depends on an accurate understanding and proper handling of cervical anatomical structures. As a key anatomical landmark, the middle cervical fascia plays a critical role in thyroid lobe resection and precise identification of the recurrent laryngeal nerve (RLN) during thyroid surgery. However, existing anatomical literature provides limited descriptions of the middle cervical fascia and surrounding spaces. This study was performed to explore the anatomical characteristics of the middle cervical fascia and its adjacent spaces in detail, providing more accurate anatomical evidence and practical guidance to improve the safety and efficacy of thyroid surgery.Methods First, systematic anatomical studies were conducted on formalin-fixed cadaveric specimens. During the dissections, the structural features of the middle cervical fascia and its surrounding spaces were meticulously recorded, with special attention to its relationships with the thyroid gland, common carotid artery, and infrahyoid muscles. Second, real-time observations and records were made during thyroid surgery on patients with thyroid cancer. The appearance of the middle cervical fascia and changes in related anatomical structures were documented during surgery.Results Both cadaveric dissections and intraoperative observations revealed that the middle cervical fascia is closely attached to the thyroid gland medially, while laterally it extends across the surface of the common carotid artery to the infrahyoid muscles. When the fascial plane was incised, important structures such as adipose tissue, lymph nodes, RLN, middle thyroid vein, inferior thyroid artery, and inferior thyroid vein were clearly observed. Additionally, it was found that the RLN is enveloped by a thin layer of fascia and adipose tissue. Intraoperative findings showed that RLN exposure techniques based on the middle cervical fascia significantly facilitated RLN identification and improved surgical efficacy.Conclusion The middle cervical fascia is a key supportive structure on the thyroid surface and an independent fascial plane critical for tissue dissection and precise RLN exposure during thyroid surgery. A deeper understanding of the anatomy of the middle cervical fascia and its surrounding spaces is essential for ensuring the safety and effectiveness of thyroid surgery.