This invention provides preparations, compositions, products, and applications of photo-crosslinked hydrogels. Component A—；a photosensitive polymer derivative, component B—；the photoinitiator, and auxiliary component C—；other biocompatible polymer derivative each are respectively dissolved in a biocompatible medium to obtain solution A, solution B, and solution C. The solution A, the solution B, and the optional solution C are mixed homogenously to obtain a hydrogel precursor solution. The hydrogel precursor solution is subject to irradiation of the UV light for photocoupled crosslinking to form a photo-crosslinked hydrogel. The photo-crosslinked hydrogel exhibit rapid speed of photo-curing, strong tissue adhesion, excellent mechanical properties, good biocompatibility, and excellent clinical operability. In addition, this invention also provides a kit for making the photo-crosslinked hydrogel, and applications thereof in tissue engineering, regenerative medicine, 3D printing, and as a carrier of cell, protein, or drug.
