The invention provides a starting protection device and method suitable for a maritime work folded arm type crane hydraulic system under the low-temperature work condition. The starting protection device comprises a hose protection device, a steel pipe protection device, an oil cylinder protection device and a PLC monitoring system. The hose protection device adopts a novel heating heat preservation hose and is connected with a sensor to conduct feedback and temperature control. In the steel pipe protection device, a small automatic temperature control electric heating belt is used for conducting winding and is fixed through a low-temperature resisting steel ribbon, and a sensor is externally arranged for conducting temperature control. In the oil cylinder protection device, a large automatic temperature control electric heating belt is adopted for conducting winding and is fixed through a welding ring, and a sensor is externally arranged for conducting temperature control. The PLC monitoring system is used for collecting data transmitted by the sensors and controlling switches of all parts of heating devices, and when the temperature is in the set range, the hydraulic system starting protection device is controlled to stop heating.