The present invention relates to a tag for identifying an object image, including: a feature changing module, including multiple light sources and changing intensity and a wavelength of the light source according to a feature signal; and a communication module, receiving a feature signal generated from the feature changing module, and sending an output signal related to the feature signal. The present invention further relates to a device for identifying an object image, including: a communication module, where the communication module receives a feature signal, where the feature signal includes a command or related information for controlling multiple light sources; a processing unit, where the processing unit receives the feature signal and an image signal from an image sensor, and generates an image identification result according to the image signal and the feature signal; and a storage module, used for storing the image identification result. The present invention can precisely identify an object and provide features related to the object to be identified without using a complex image identification algorithm or a technology for improving resolution of an image.