Character input method, device and system

A character input method, device and system, which relate to the field of application of electronic technologies. The method comprises: receiving a first character inputted by a user (201); determining a second character set associated with the first character, the second character set comprising at least one second character (202); querying for a correspondence between characters and key identifies, and obtaining a target key identifier corresponding to each second character (203); and controlling a key lamp corresponding to a target key indicated by the target key identifier to emit light having a preset color, the light having a preset color being used for prompting a user to perform character input (204). The method, the device and the system resolve the problems of low input efficiency and high possibility of incorrect input in the related art, and the effects of improving the input efficiency and avoiding wrong input are achieved, and the method, the device and the system are used for input prompting.