Engine control method and system

The invention discloses an engine control method and system. The engine control method comprises the steps of: receiving generator position signals acquired by a rotary change sensor; receiving piston signals, acquired by a cam shaft sensor, of each cylinder piston of an engine; determining a crank angle according to the generator position signals and the position signals of each cylinder piston of the engine; and determining states of each cylinder of the engine according to the crank angle, and controlling the engine according to the state of each cylinder of the engine. The engine control method and system cancel such complex parts as a crankshaft position sensor, a crankshaft disc and an indexing plate, reduces the hardware cost, and can precisely control the engine through coaxial connection of a generator and the engine.