Hydrogels are generally regarded as biocompatible materials for cell therapy,tissue engineering,drug delivery and many other biomedical applications.Recently,there has been a focus on a new generation of dynamic hydrogels that are capable of responding to artificial triggers and biological signals with great precision[1].Among the stimuli to induce controlled degradation of hydrogels,light showed great advantages such as non-invasiveness as well as temporal and spatial control with high precision[2].However,most photo-degradable hydrogels consist of o-nitrobenzyl or azobenzene,which require multi-step synthesis and tedious purification procedures.