Jacking beam anti-drop device

The utility model provides a jacking beam anti-drop device which can ensure that a hanging plate and a step are firmly positioned in a jacking or descending process of a self-elevating tower crane, so that a jacking beam is firmly supported on a tower body support structure to guarantee safety. The jacking beam anti-drop device comprises a jacking beam, a hydraulic oil cylinder support, a standard knot, a step and a hanging plate, wherein the step is welded on the standard knot, the hydraulic oil cylinder support is arranged at the middle part of the jacking beam, the upper part positions at the two side parts of the jacking beam are firmly connected with the lower part of the hanging plate respectively, and the upper part of the hanging plate is hung in a mounting slot of the step on the corresponding side. The jacking beam anti-drop device is characterized in that the hanging plate is divided into an inner-side hanging plate and an outer-side hanging plate, a bolt hole is formed in the inner-side hanging pl