The invention discloses a plastic optical fiber and a process of knitting a knitted fabric by virtue of the plastic optical fiber, and belongs to the technical field of optical fibers. The plastic optical fiber is obtained from cadmium selenide quantum dot-containing fiber core particles and nanometer silicon dioxide-containing cladding particles by a double-head extrusion method, obtained plastic optical fibers and blended yarns are knitted through a hand-operated flat knitting machine, a 5mm high-brightness blue LED (Light-Emitting Diode) lamp is used as a light source, and the plastic optical fibers with certain lengths are reserved at the two ends of the knitted fabric for bundling and cutting treatment. According to the plastic optical fiber and the process, a formula and a process of the plastic optical fiber are improved, so that the light intensity, the ductility, the flexibility, the flexing resistance, the wear resistance and the impact resistance are obviously improved, and the development of the plastic optical fiber in knitted fabrics is greatly promoted.