Provided is a leak-proof lubrication system for a power device, comprising an oil supply pump inlet pipe, an oil supply pump, an oil supply pressure gauge, an oil supply pump outlet pipe, an oil supply filter, a lubricating oil, an oil storage tank, an oil return pipe, an storage tank pressure gauge, a vacuum pump intake pipe, a vacuum pump inlet air filter, a vacuum pump and a vacuum pump exhaust pipe. The system employs a negative pressure operation method in which the pressure of the lubrication system is controlled to be lower than the outside ambient pressure, which allows a small amount of air to flow from the outside to the inside of the lubrication system along with the lubricant to return to the storage tank, preventing leakage of the lubricant from connection joints. It is suitable to be used for gas turbines or other high-speed power machines.