Abstract: The LJ4 K18 QS dual-fuel engine is modeled with the modeling and simulation software GT-Power. Ethanol-reformed gas is injected to the Engine to further develop the model of the engine with the reformer. A map is produced showing the optimal ignition advance Angle against engine speed and load under the reformed ethanol mode. The research indicates that for a given load, the ignition advance angle needs to be increased as the speed increases, and for a given speed, it needs to be reduced as the load increases.