Crane variable amplitude control system and control method thereof

The invention relates to the technical field of engineering machinery, and discloses a crane variable-amplitude control system and a control method thereof, the crane variable-amplitude control system comprises a variable-amplitude oil cylinder, a variable-amplitude handle, a hydraulic oil tank, an oil pump, a balance valve, a pressure sensor and a controller; a rodless cavity of the variable-amplitude oil cylinder is connected with a port C of the balance valve; a port A1 of the balance valve is sequentially connected with the oil pump and the hydraulic oil tank; the pressure sensor is connected with a rodless cavity of the variable-amplitude oil cylinder and used for detecting the oil pressure P of the rodless cavity of the variable-amplitude oil cylinder and sending the collected oil pressure value P to the controller, and the controller is used for receiving a working signal transmitted by the variable-amplitude handle and the oil pressure value P monitored by the pressure sensor in real time and controll