Mobility without changing the IP address is the key to the mobile IPv6.The key technology for mobile IPv6 is the mobile switching process.How to reduce the switching delay is the standard to measure the function of the mobile IPv6 switch.For this reason,as for the mobile host’s frequent switching in the field network we propose the  Hierarchical Mobile IPv6 to reduce the delay,and expect the  switch of the second layer’s trigger has made rapid switching for mobile IPv6.In this paper,we propose an improved program based on the  fasthierarchical mobile IPv6.First of all,for the delay of fast switching,it introduces the caching mechanism,and then because MAP can not reduce the registration delay when interdomain switching happens,it introduces the concept of functional router.We propose the optimal function of the routing algorithm to reduce the handoff delay and the packet loss rate.The experimental analysis shows that the new method has a high degree of improvement.