Hydrogel optical light-guides have received substantial interest for applications such as deep-tissue biosensors,optogenetic stimulation and photomedicine due to their biocompatibility,(micro)structure control and tissue-like Young\'s modulus.However,despite recent developments,large-scale fabrication with a continuous synthetic methodology,which could produce core-sheath hydrogel fibers with the desired optical and mechanical properties suitable for deep-tissue applications,has yet to be achieved.In this study,we report a versatile concept of integrated light-triggered dynamic wet spinning capable of continuously producing core-sheath hydrogel optical fibers with tunable fiber diameters,and mechanical and optical propagation properties.Furthermore,this concept also exhibited versatility for various kinds of core-sheath functional fibers.The wet spinning synthetic procedure and fabrication process were optimized with the rational design of the core/sheath material interface compatibility[core =poly(ethylene glycol diacrylate-co-acrylamide);sheath =Ca-alginate],optical transparency,refractive index and spinning solution viscosity.The resulting hydrogel optical fibers exhibited desirable low optical attenuation(0.18 ± 0.01 dB cm-1 with 650 nm laser light),excellent biocompatibility and tissue-like Young\'s modulus(＜ 2.60 MPa).The optical waveguide hydrogel fibers were successfully employed for deep-tissue cancer therapy and brain optogenetic stimulation,confirming that they could serve as an efficient versatile tool for diverse deep-tissue therapy and brain optogenetic applications.