An practical few-mode fiber with elliptical pure SiO2 core was designed for large-capacity optical communication systems. The design principle and reference standard are presented, and the transmission properties were analyzed with full vector finite element method combined with perfectly matched layer boundary conditions. At the wavelength of 1.4~1.65 μm, the fiber is in stable dual-mode operation with modes HE11 and HE21, and the effective refractive index difference between the modes is greater than 1.8×10-3, which can avoid the mode coupling and crosstalk. At the wavelength of 1.55 μm, the chromatic dispersion of the modes HE11 and HE21 is 19.61 and 4.41 ps/(nm·km) respectively, the dispersion slope is 0.048 and 0.002 ps/(nm2·km) respectively, the mode field area is 97.17 and 143.96 μm2 respectively, and the attenuation coefficient of each mode is less than 0.21 dB/km. Transmission properties of the fiber can basically meet the G.652 and G.655 fiber standards, and it can be made by the existing mature “preform drawing” technology. This is significant for the promotion of next generation communication network bandwidth, which can be combined with WDM technologies to increase optical network transmission capacities exponentially.