Unified Power engage Jichai for Jichai gas generator for continuous usage. Whole engine is optimized by amending the shortages of the first gas engine generation. The power performance, fuel economy and reliability of this Jichai gas generator are improved a lot by adopting inner mixing mode, increasing compression ratio and boost ratio, enhancing swirl ratio, realizing lean-burnt by controlling air fuel ratio, using high-energy ignition. This engine series is mainly used in generating by single engine or several engines forming a power station. It also can be used as power of compressor, oil transfer pump, water injection pump.