Abstract: Objective: Turnout is a critical equipment in rail transportation system and an important focus of supervision in signaling control system. To improve the operational level of rail transit turnout, research is carried out on the onsite turnout monitoring technology. Method: The relevant technical requirements of turnout monitoring technology are analyzed. Detailed research and design are conducted on key technologies for onsite turnout monitoring to ensure the correct functionality of turnouts when adopting the onsite local control technology. Taking a set of CN6118AS turnouts controlled by 5 devices as object, the turnout monitoring experiments are carried out to study the application situation of the onsite turnout monitoring technology. Result & Conclusion: Based on the application effectiveness of the turnout monitoring experiment, the onsite turnout monitoring technology demonstrates clear control priority and reliable switching functionality. Its safety, reliability, maintainability, and availability meet the professional standards of signaling, showing promising prospects for widespread application.