In nested mobile network, traffic should be encapsulated and tunneled for each level of nesting, which leads to increased overhead and sub-optimal routing. In this paper, we investigate a localized mobility management framework and propose a source routing binding update mechanism based on mobile anchor point (MAP) to optimize the route of nested mobile network that supports NEMO basic support protocol (NBS). Following superiority can be achieved with this scheme: 1) An one-way tunnel is built between top level mobile router (TLMR) and its home agent (HA) to accomplish route optimization. 2) The localized framework reduces mobility registration overhead and boosts the mobility management performance. We also builds an analysis model for performance evaluation, through quantitative comparisons with existing schemes, our scheme triumphs in terms of packet delivery overhead and mobility registration costs.