A new kind of optical fiber corylic resin coating was prepared in this paper. The influence of PVC (pigment volume concentration) to the properties of coatings was studied. The best formula was selected. The best coating was painted on the optical fiber. The relationships of the coating diameter and the distances of the centers of the coating layer and optical fiber were studied. It was found that the circle diameter of coating is greater; the distance of centers of circles is bigger. Finally, the optical fiber with this coating was embedded in resin castings. The cross sections were observed under the same heated situation. The results revealed that the coatings embedded in composites used in large aircraft had no change when it was heated. This kind of coating did not need ultraviolet light or heating, and it’s easy to control the thickness and roundness of the coating by controlling the speed of pulling out the optical fibers. This type coating is a kind of simple heat-resistant coating embedded in composite materials used in the large aircraft.