Proxy Mobile IPv6 (PMIPv6) is the network-based localized mobility management protocol proposed by IETF. The local mobility anchor (LMA) and the mobile access gateway (MAG) are the key entities realizing the system function of PMIPv6. To solve the reliability problem of PMIPv6 MAG, this paper proposes an MAG faulttolerant method based on pool (MAGFT). MAGFT introduces MAG pool to realize MAG fault-tolerant. Several MAG pools are constructed in an PMIPv6 domain, and each MAG belongs to at least one of the pools. When an MAG fails, a given MAG in the same pool will take over. The results of theoretical analysis and simulation show that the fault-tolerant latency of MAGFT can be restricted within 35ms~340ms. When the fault-tolerant latency is lower than 120ms, MAGFT can avoid the influence of MAG failure on MNs’ up-layer TCP applications. In the worst condition, MAGFT can resume an MN’s TCP throughput within 1.1s, 1.6s, and 2.8s respectively when the MN resides in WLAN, 3G or satellite network. For the upper applications based on UPD, MAGFT can resume MNs’ packet rate within 2s after the occurrence of an MAG failure. At the same time, MAGFT introduces low signaling cost, which can be neglected when compared with the PMIPv6 signaling. MN’s access delay introduced by MAGFT is no more than 10ms.