The invention provides a common-rail fuel oil jet system controlled by double electromagnetic valves and applied to a low-speed diesel engine for a ship. The common-rail fuel oil jet system comprises a fuel oil supply portion and a common-rail jet device. The fuel oil supply portion supplies fuel oil and servo oil to the common-rail jet device. In the common-rail jet device, an upper pressurizing piston cavity and a lower pressurizing piston cavity are formed between a pressurizing piston and a pressurizing piston body, and the pressurizing piston control valve controls the fuel oil supply portion to be communicated or not communicated with the upper pressurizing piston cavity, so that fuel oil pressurization or fuel oil suction is achieved; the electromagnetic fuel oil jet control valve conducts fuel oil-working-condition accurate flexible control over fuel oil jet timing and the circulation jet amount, a pressurized high-pressure fuel oil path in the lower pressurizing piston cavity is divided into two paths, one path reaches a control cavity, and the other path reaches a fuel oil containing groove. According to the common-rail fuel oil jet system, the two electromagnetic valves are used for control, fuel oil is used as fuel and servo oil at the same time, the structure is simplified, cost is reduced, mutual independence between fuel oil pressurization and jet and repeated jet are achieved, fuel oil jet timing, the fuel oil jet rule and the circulating fuel oil jet amount are more accurately controlled, the fuel oil economical efficiency and the emission performance of the diesel engine are improved.