Light-responsive ionic liquids(ILs) are a class of functional materials that combine the characteristics of light stimuli responsive materials and ILs. Upon UV/vis light irradiation, the structure, property and performance of these “smart” ILs can be significantly changed, which are expected to have important applications in many practical processes. Light trigger is of great importance because of its superiority, such as stable optical signal, accurate stimulation spot, and ability to be rapidly switched in a clean and non-invasive manner. In this work, the photo-isomerization of ILs and light modulation of IL properties, aggregation behavior of ILs, phase transfer of ILs, and phase behavior of emulsions involving IL are critically reviewed based on the structure-property-performance relationship of photo-responsive ILs. Meanwhile, the main problems in this field have been analyzed, and the future development is discussed.