The invention relates to the field of engineering machinery, and discloses a reversing valve, a control device of variable amplitude reverse impact of crane and a crane. The reversing valve comprisesa valve body provided with a first working oil port, a second working oil port, an oil inlet, a first oil return port and a second oil return port, the main valve cavity of the valve body comprises avalve core matching cavity and a valve core capable of reciprocating in the valve core matching cavity, the range of travel of the valve core includes at least a first working position and a second working position for controlling the movement of the hydraulic actuator element in a direction opposite to each other, a middle position between the first working position and the second working position and a first transition position between the first working position and the second working position, in the case of the valve core in the first transition position the first working oil port is communicated with the first oil return port, and the second working oil port is communicated with the oil inlet and the second oil return port. By the method and the device, the stability and the speed ofthe variable amplitude fall of the engineering machinery can be guaranteed, and the reverse impact when the amplitude variation fall is stopped can be avoided.