Noiseless starting gasoline engine and starting method thereof

The invention relates to a noiseless starting gasoline engine and a starting method thereof. The engine comprises a cylinder block, a combustion chamber disposed in the cylinder block, an oil sprayer mounted in the combustion chamber and a sparking plug. The oil sprayer is connected to the output end of an oil spraying controller. The sparking plug is connected to the output end of an ignition controller. A piston is mounted in the cylinder block and connected with crankshaft through a piston rod. A flywheel is connected to the crankshaft. The input end of the oil spraying controller is connected to the output end of the oil spraying control circuit. The oil spraying control circuit comprises an oil spraying AND gate circuit, an acting cylinder signal generator and a ignition signal generator, wherein the acting cylinder signal generator and the ignition signal generator are connected to the input end of the oil spraying AND gate circuit. The ignition signal generator comprises an ignition ANG gate circuit, a starting signal sensor, a crankshaft position sensor and a rotation speed sensor, wherein the starting signal sensor, the crankshaft position sensor and the rotation speed sensor are connected to the input end of the ignition ANG gate circuit. The input end of the ignition controller is connected with the output end of the square signal generator. The input end of a square signal generator is connected to the output end of the ignition signal generator. The gasoline engine can be started without a motor, is short in starting time and noiseless, and production cost of the motor and storage batteries can be saved.