The invention relates to a leakage protecting system for oil tubes of an engine and belongs to the technical field of engines. The leakage protecting system for the oil tubes of the engine comprises the double-layer oil tubes enabling an oil injection pump and an oil injector to communicate and a drainage tube enabling the double-layer oil tubes and a fuel oil alertor to communicate. By designinghigh-pressure fuel oil tubes into the double-layer oil tubes and arranging the corresponding fuel oil alertor, a fault is found out at the earliest time and treated timely under the condition that thefuel oil tubes are broken, leaked fuel oil is collected, the situation that a fire occurs due to the splashing fuel oil is prevented, and personal and property safety is guaranteed. The leaked fuel oil can be recycled after being treated, so that resources are further saved. The structure is simple, detaching is convenient, maintenance is easy, and working is stable and reliable; the leakage working condition of the double-layer oil tubes can be monitored visually in real time; compared with a manual monitoring mode, the monitoring efficiency and the monitoring accuracy of the leakage protecting system for the oil tubes of the engine are improved greatly, and meanwhile the labor intensity of workers is further reduced; and the comprehensive using performance of the leakage protecting system for the oil tubes of the engine is good.