Herein, we introduce a variety of azopolyesters (azobenzene‐based polyesters) with remarkable intrinsic crystallinity and photoinduced reversible solid‐to‐liquid transition abilities from copolymerization of azobenzene‐based epoxides with cyclic anhydrides. The length of the soft alkyl side‐chain inlaid with azobenzenes and stereoregularity of main‐chain of azopolymers have tremendous effects on crystallization properties of the resulting polyesters with melting temperature (Tm) in the range of 51–251 °C. Moreover, some of azopolyesters possess excellently photoinduced reversible solid‐to‐liquid transition performance thanks to trans‐cis photoisomerization of azobenzenes. Trans‐azopolyesters are yellow solids with Tms or glass transition temperatures (Tgs) above room temperature, whereas cis‐polymers are red liquids with Tgs below −20 °C. These azopolyesters could be applied as novel light‐switchable adhesives for quartz/quartz, wood/wood and quartz/wood adhesion, with the strength in the range of 0.73–0.89 MPa for trans‐polymers. Conversely, the adhesion strength of liquefied cis‐azopolyesters generated from the irradiation of trans‐polymers by UV light was about 0.1 MPa, which shows light enable to control the adhesion process with high spatiotemporal resolution. Azobenzene‐based polyesters (azopolyesters) from copolymerization of azobenzene‐based epoxides with cyclic anhydrides possess remarkable intrinsic crystallinity and novel photoinduced reversible solid‐to‐liquid transition abilities, owing to photoinduced trans‐cis isomerizations of azobenzenes being inlaid with soft alkyl side‐chain. This represents a new design strategy for the synthesis of reversible adhesives.