Cooled exhaust gas recirculation (abbreviated as cooled EGR) technology can effectively enhance engine fuel economy and suppress detonation while significantly improve engine emissions. Through numerical analysis, the mechanisms for optimizing the fuel economy of high-compression-ratio hybrid engines equipped with cooled EGR technology were investigated. Comparative analyses of engine performance, fuel consumption and combustion strategy were conducted under  full load conditions of baseline engine and partial load conditions of cooled EGR engine. The lowest fuel consumption point and the corresponding optimal combustion strategy were obtained under different conditions. The study provides a theoretical basis and technical support for the optimization of fuel consumption in hybrid dedicated engines.