The utility model discloses an online steel wire rope detecting device, which comprises a fixing rod, Hall sensors and displacement sensors. A cross rod is in pin joint with a positioning hole on the fixing rod by a movable pin, a rope penetrating hole is disposed at an axle center of a fixing part, the Hall sensors are mounted in a cavity at the center of the fixing part, the rope penetrating hole penetrates through the cavity at the center of the fixing part, the Hall sensors are uniformly distributed on the periphery of a steel wire rope, the fixing part is fixed onto the fixing rod, positioning wheels are mounted at two ends of a connecting frame, the displacement sensors are mounted on the positioning wheels, the connecting frame is fixed to the upper side of the fixing part, the upper portion of a spring is attached to the cross rod, the lower portion of the spring is embedded into a spring hole on the fixing part and elastically contacts with the Hall sensors, and the lower end of the fixing rod is in screwed connection with a base. The online steel wire rope detecting device adopts the fixing rod, the fixing part, the Hall sensors mounted in the cavity of the fixing part, the connecting frame and the like are fixed onto the fixing rod, the lower end of the fixing rod can be fixed onto an optional base conveniently, and real-time detection can be realized at any time without a worker holding the online steel wire rope detecting device by hands.