Floating crane load power take-off device and method and floating crane

The invention relates to a floating crane load power take-off device and method and a floating crane. The floating crane load power take-off device comprises a base, the base is rotationally connected with the non-end position of a rotating rod, one end of the rotating rod serves as a power take-off end, a pressure detection element matched with the power take-off end is arranged at the top end of the base, and the other end of the rotating rod serves as a stress end; the stress end of the rotating rod is hinged to one end of a connecting mechanism, the other end of the connecting mechanism is used for being connected with a steel wire rope of the floating crane, the bottom end of the base is further in threaded connection with an adjusting piece, and the adjusting piece makes contact with the stress end of the rotating rod so that the force taking end of the rotating rod can apply set initial pressure to the pressure detection element. The load power take-off device is higher in precision. 本发明涉及一种浮式起重机负荷取力装置