The invention relates to a low dispersion slope dispersion-shifted single-mode fiber for large capacity transmission comprising a core and a cladding. Said fiber is characterized in that said core has three to five core segments having different refractive index profiles, and said cladding has four to six cladding segments. The total dispersion slope of said fiber at 1550 nm is less than 0.060 ps/nm²km, the zero dispersion wavelength is less than 1420 nm, the effective area ranges from 55 m² to 65 m², and the dispersion in the region of 1530 nm1565 nm ranges from 5.0 ps/nm²km to 12.0 ps/nm²km. The fiber has low dispersion slope, moderate dispersion, low attenuation, and excellent bend resistance performance. It is suitable for a high-speed (10 Gbits/s and 40 Gbits/s), large capacity, and long distance DWDM system. Therefore, not only the non-linear problem that fazes high-speed communication is solved effectively, but also the DWDM transmission at 10 Gbits/s can be realized within a wider wavelength range. In addition, low dispersion slope is advantageous for comprehensive management of dispersion, so that the requirement for long distance non-electric relay can be fulfilled.