Locally advanced differentiated thyroid carcinoma (DTC) frequently invades the aerodigestive tract, recurrent laryngeal nerve (RLN), trachea, larynx, esophagus, and occasionally major blood vessels. Such invasion can significantly impair phonation, respiration, and swallowing, thereby reducing both prognosis and quality of life. Because invasion typically begins superficially and gradually progresses inward, management requires a careful balance between achieving durable local control and preserving essential functions. Although no definitive consensus exists regarding the optimal extent of organ resection in locally advanced DTC, many authors endorse a functional preservation strategy. Shave excision is widely accepted for superficial invasion, as microscopic residuals rarely influence recurrence or survival, whereas combined resection with appropriate reconstruction is recommended for intraluminal or deep invasion to ensure oncologic safety. Invasion may occur not only directly from the primary tumor but also through metastatic lymph nodes, often involving multiple organs and necessitating highly complex procedures. Therefore, decisions regarding surgical intervention should be made by an experienced multidisciplinary team (MDT). Such decisions must incorporate a thorough assessment of tumor extent, surgical risks, technical feasibility, and anticipated postoperative quality of life, particularly regarding phonation and swallowing, while also considering the patient’s overall prognosis and life expectancy. This concept—aggressive but function-conscious surgery guided by MDT evaluation—represents the core principle in managing locally advanced DTC. Treatment strategies vary according to the invaded structure. RLN preservation with shave excision is appropriate for superficial epineurial involvement, while severe infiltration requires nerve resection with immediate reconstruction to restore phonatory stability. Tracheal invasion is managed with shave excision for superficial disease and with sleeve or window resection for intraluminal invasion. Laryngeal and esophageal invasion often allows partial resection while preserving organ continuity, with total laryngectomy reserved only for extensive disease. Subadventitial resection is feasible for most great vessel invasions, although arterial reconstruction becomes necessary when deeper layers are involved. Surgical approaches for parapharyngeal and mediastinal metastases should be selected based on anatomical complexity and surgical exposure. When performed with appropriate case selection and expertise, these tailored strategies can achieve favorable long-term outcomes even inpatients with complex, locally advanced DTC.