The dynamic changes of the topology caused by the movement of nodes makes routing become one of the key problems in the mobile Ad Hoc Networks (MANET). So how to optimize routing becomes a hot and difficult topic, among which optimizing routing cache is one of the key techniques. In this paper, we propose an adaptive dynamic cache routing (DCR) strategy based on DSR (Dynamic Source Routing), which can evaluate the link expiration time rapidly. The experimental results show that the DCR has considerable improvement in control packets, packet delivery ratio, packet drops and end-toend average delay in the MANET.