The invention provides a light supplementing method and device, and a mobile terminal. The mobile terminal comprises at least two flashes arranged in a camera direction. The method comprises the following steps: when the camera performs picture-photographing preview, detecting the current color temperature of a photographed preview image; determining target light supplementing information according to the current color temperature; determining a first target flash that needs to be started according to the target light supplementing information, wherein the first target flash is at least one flash in the at least two flashes, the at least two flashes comprise at least one first flash and at least one second flash, and the color temperature of the first flash is different from that of the second flash; and controlling the first target flash to be started. According to the light supplementing method provided by the invention, intelligent color temperature compensation can be carried out on the image photographed by the camera, so that the photographed image can have a plurality of color temperatures and user requirements are satisfied.