The present application discloses a medical path navigation method, planning method and system. The navigation method includes: planning a navigation path; delivering an ablation catheter with a localization sensor into an airway leading to a lesion region according to the navigation path; adjusting a position and a direction of the ablation catheter in the airway based on the localization sensor during a moving process of the ablation catheter in the airway until the ablation catheter is navigated to a planned initial ablation region; and adjusting a position and a direction of the ablation catheter in the lesion region based on the localization sensor during a moving process of the ablation catheter in the lesion region until the ablation catheter is navigated to other ablation regions. The embodiments of the present application may accurately navigate the ablation catheter to a lesion position that is not reachable by a bronchoscope, such as positions at the periphery of the lung, so that the ablation catheter is no longer subjected to a reachable range of the bronchoscope.