A layered water injection system and a layered water injection method. The system comprises: a ground water injection valve group configured with an intelligent control valve, for receiving a water injection control instruction sent by a remote control center, and for converting the water injection control instruction into a switching action of the intelligent control valve to control water flow pressure fluctuation in a water injection string, so as to form a first pressure wave code in the water injection string; a water distributor for collecting the first pressure wave code, interpreting the first pressure wave code as a corresponding water outlet switch instruction, and performing layered water injection control according to the water outlet switch instruction. The embodiments of the application can improve the automation level of layered water injection and the reliability of layered water injection control.