Herein, we report a feasible method to prepare a tadpole-shaped PEG-POSS-(Azo)7 polymer. The polymer self-assembled into a large vesicle in aqueous solution, undergoing reversible smooth-curling transformation responsive to UV and dark conditions. Incorporating POSS units into the azopolymer furnished quick trans–cis isomerization along a cubic orientation. The orientational isomerization formed some pores on the vesicular membrane and endowed the highly sensitive photoresponsive property. Encapsulation of various fluorescent dyes affected the hydrophilic/hydrophobic ratio of self-assemblies, causing their morphological transition from vesicles to micelles. Response to UV irradiation, the quick trans–cis isomerization resulted in rapid release of the encapsulated dyes. The intriguing photoresponsive property renders this kind of tadpole-shaped POSS hybrid azopolymer a potential for application in controlled release of drug.