The invention belongs to the engine manufacturing technical field, in particular relating to a direct injection engine for injecting water and oil into a cylinder. The invention provides a direct injection engine, which comprises the cylinder, a combustion chamber, a water supply device, an oil supply device and an electronic control system which can simultaneously perform water injection and oil injection, wherein, a gas inlet valve, a gas outlet valve and a spark plug are respectively arranged above the combustion chamber; a water nozzle and an oil nozzle which are electrically connected with the electronic control system are respectively arranged on the cylinder; the water nozzle and the oil nozzle are arranged oppositely; and the water supply device and the oil supply device are respectively communicated with the water nozzle and the oil nozzle. Compared with the prior art, the direct injection engine not only can realize fuller combustion of oil, save the fuel oil and prolong the service life of the engine but also can reduce the pollutants in the exhaust gas exhausted by the cylinder and play a part in environmental protection.