Catenary ladder trolley with movable rail grabbing device and control method

The invention discloses a catenary ladder trolley with a movable rail grabbing device and a control method, and particularly relates to the technical field of rail grabbing and falling prevention of rail trolleys, the catenary ladder trolley comprises a ladder trolley frame and a sliding seat sliding on a steel rail head, and the sliding seat is fixedly installed on the bottom face of the ladder trolley frame. Through work of the winding mechanism, a steel rope starts to be wound to lift a lifting plate until the lifting plate moves to the height flush with a cross rod at the bottom of the protective barrier, a winding shaft rod stops winding and enables a ratchet wheel to stop rotating, and then a rotating air cylinder drives a braking pawl on a transmission cross rod to rotate to the surface of the ratchet wheel; the ratchet wheel is limited, so that the winding shaft rod is locked, loosening and deviation of the winding shaft rod are avoided, it is guaranteed that the ratchet wheel is limited by the stable