回顾了汽油机缸内喷水的系统分类以及机理研究，对汽油机的喷水策略进行了讨论和总结。指出喷水时间和喷水器安装位置是影响进气道喷水能否顺利进入缸内进行蒸发吸热的重要因素，而对于缸内直接喷水来说，喷水时间和喷射压力是影响缸内最终降温效果的重要优化参数。重点阐述了喷水在抑制爆震、取消燃油加浓、扩大压燃运行区域等方面已经取得的研究成果，将喷水技术与传统的EGR技术进行对比分析，对未来喷水技术大规模应用的局限性进行了探讨。

The system classification and mechanism research of water injection in the gasoline engine were reviewed and then the water injection strategy of gasoline engine was discussed and summarized. The water injection timing and the position of water injector were thought to be important factors that would affect whether the injected water in the intake port could enter the cylinder and cause the heat absorption by evaporation successfully or not. The water injection timing and pressure were important optimization parameters that would affect the incylinder cooling effect for the incylinder water injection technology. The research fruits of water injection such as suppressing knock, eliminating fuel enrichment and expanding the compression ignition operation area were mainly introduced. In the end, the limitations of largescale application of water injection technology in the future were discussed by comparing it with traditional EGR technology.