A VMN-based MIPv4 fast handoff method based on the basic MIP/AAA model was presented for satisfying the users' demands of security and low latency in MIP services and making up the existing insufficiency in the current MIPv4 handoff method. The method strengthens the basic MIP/AAA model, and sets up a novel data structure in the mobile agents. Through establishing a new bidirectional tunnel between NFA and OFA, it fast transforms the data packets of VMN between them, and realizes the fast low latency handoff under no data packets losing. Through distributing the new temporary security association and the authentication ticket, it enhances the security in the MIP's registration and handoff process, and effectively reduces the network loads between AAAH and the AAAF. The secure analysis and the simulation experiment for the presented method indicates that the method is more secure and effective.