Crane rotation control method, device, system and crane

The invention provides a crane rotation control method, a device, a system and a crane, which are used for solving the problem that a rotation control effect of a crane used for flexibly connected with a hung heavy object is poor in the prior art. The method includes that an included angle between a hang rope and the vertical direction is preset according to the current working condition of the crane, and rotation linear speed of the hung heavy object is obtained according to current rotation linear speed of a rotation mechanism of the crane, the length of an oscillating assembly formed by the hung heavy object and the hang rope and the included angle; and when the rotation linear speed of the rotation mechanism exceeds the rotation linear speed of the hung heavy object by a value larger than a first preset value, rotation speed of the crane is reduced. The crane rotation control method, the device, the system and the crane adopt the technical scheme, and are beneficial for reducing impact of the heavy object, a tangential deflection angle of the heavy object and impact load of the head of a suspension arm under the condition of meeting requirements on stability of a vehicle, structural strength and rigidity, and accordingly operational safety is guaranteed.