The Hilink DCM model is a negative dispersion optical fiber launched by Hilinktech Co. , Ltd. , which is a new type of single mode optical fiber designed for presently laid G.652& G.655standard single-mode optical fiber; the dispersion of G.652 optical fiber in the vicinity of 1550nm wavelength is positive (17-20) ps/nm (km), and the dispersion of G.655 standard optical fiber in the vicinity of 1550nm wavelength is positive (4-6) ps/nm (km), with a positive dispersion slope. So we need to add dispersion compensation fiber with negative dispersion into the optical fiber then conduct the dispersion compensation and make sure that the total dispersion of the whole optical fiber links is near zero, so as to realize high speed, large capacity and long distance communication.