Parallel steel strand cable-stayed bridge before and after the bridge is generally a single tensile long-term fixed repetitive pulling 1, 5, 10... The method of testing the cable force of the steel strand, often pulling will increase the bite mark displacement of the tensioning end clip and the possibility of sliding wire, which will affect the safety of the stay cable. The flat integral cable force detection method is adopted, which does not loosen the clip, improves the test efficiency and accuracy, and increases the safety of the cable. The magnetic flux measurement method is adopted for cable force monitoring. The sensor is simulated and calibrated in the factory first, and then wound directly in the field. It is a non-destructive and non-contact measurement method, which is especially suitable for long-term monitoring of cable force after bridge completion. Based on the research and practice of the overall cable force detection and monitoring scheme of Yiling Yangtze River Bridge, this paper explores how to safely detect and monitor the cable force of the completed bridge.