Objective We aim to design and conduct hydro-dissection for improving the safety and curative effects of ultrasound-guided percutaneous thermal ablation therapy of neck nodular lesions. Methods Percutaneous thermal therapy by using radiofrequency ablation or microwave ablation was carried out on 1126 patients suffering neck nodular diseases. As a part of the treatment procedure, ultrasound-guided injection of separating liquid into between the target nodules and surrounding structures to form a separating zone was performed prior to starting ablation. The focus of study was whether the hydro-dissection technique had improved the safety of puncture route, reduced the thermal injury to normal structures, and enhanced the curative effects of various neck nodules. Results Hydro-dissection technique had been successfully achieved in as many as fourteen parts related to thyroids, parathyroids, submandibular glands and lymph nodes. The ways of technical operations and ultrasonic features of this maneuver were well established and understood. The advantages of this maneuver was faithfully verified by the statistically significant reduction of undesirable heat damage to lesion-adjacent structures(15% without hydro-dissection down to 0.7% with hydro-dissection , P<0.01) and decrease in incomplete ablation of the lesions(7.4% without hydro-dissection down to 0.29% with hydro-dissection, P<0.01). Conclusion Proved successfully in practice, hydro-dissection technique under ultrasound-guidance is virtually simple to design, easy to control, likely to repeat and reliable to function. Application of this technique is supplementary to the safety measures involved in thermal ablation of various neck nodular lesions.