The utility model discloses a cylinder liner system of preheating before boats and ships auxiliary engine and the reserve start -up of ocean engineering host computer. The invention is in branch pipe of boats and ships auxiliary engine and the connection of ocean engineering host computer cylinder liner coolant outlet (extrinsic cycle export) end arrives the cylinder liner cooling water inner loop of reserve machine, and the cooling water pump who utilizes reserve machine to open forms the inner loop with the high -temperature water, for reserve auxiliary engine's cylinder liner heating, till being fit for the temperature that starts, generally 70 DEG C of left and right sides. The utility model discloses the rational utilization heat that produces when boats and ships auxiliary engine and ocean engineering main engine operation, heat for the cylinder liner of other reserve machines before starting provides to preheat, simultaneously self is got back to the working machine cylinder liner again and goes the cooling by cooling. The two interact, each takes what he needs, kills two birds with one stone. This kind of heating system is pure mechanical system, and the cost is lower, and is simple and convenient high -efficient. The utility model has the advantages of simplified operation, reduction equipment, reduce cost, improvement effect.