According to the construction characteristics of the optical fiber access network，the need for new single-mode optical fi- ber products which are resistant to bend is proposed in this article，and then describes the classifications of the G.657 fiber，the main technical standards of the G.657.A2 fiber and the typical ways of improving the fiber bending performance． And finally it cal- culates the number of fiber modes，cut-off wavelength，bending loss，dispersion and mode field distribution and other performance parameters of the G.657 fiber by the OptiFiber simulation system．