To provide a fuel supply system and a fuel supply method of a cylinder injection engine capable of developing high output in the cylinder injection engine.

This fuel supply system of the cylinder injection engine comprises a first fuel injection valve directly injecting a fuel into the cylinder of the cylinder injection engine and a supercharger increasing an engine intake air amount. The system also comprises a second fuel injection valve separately from the first fuel injection valve, and the fuel is supplied by using the first fuel injection valve and the second fuel injection valve in a predetermined engine load area. In the fuel supply system of the cylinder injection engine thus configured, even if the supplied amount of fuel by the first fuel injection valve injected into the cylinder is limited, the shorted amount of fuel can be supplied by the second fuel injection valve to increase the output of the engine.