Facile preparation and UV stabilization of electrospun poly(e-caprolactone) (PCL)/2-methyl-3-(trimethoxysilyl) propylester (M8POSS)/pentaerythritol tetrakis(3-mercaptopropionate) (PETM) composite fibers via thiol-ene click reaction were investigated. The morphological studies clearly showed the M8POSS and PETM macromers were excluded from PCL crystalline phase during electrospinning. The cross-linking reaction occurs in the amorphous phase of PCL fibers and possibly the fiber surface. By locking amorphous PCL chains into the crosslinked M8POSS and PETM through thiol-ene click reaction, we are able to fabricate PCL/POSS composite fibers, which can remain structural stability under UVC for longer period of time. The facile fabrication of the composite fibers via thiol-ene click reaction reported here provided valuable insight into not only the surface coating of medical devices but also new biocompatible composite materials.