The characteristics of nodes moving arbitrarily and the network topology changing frequently lead to AODV routing protocol, which uses minimum hop-count as the metric for route selection, facing intermittent connectivity frequently which would cause QoS of network degradation in Ad Hoc Network. In this paper, we integrate three cross layer infor-mation which consists of the remaining energy of nodes, the remaining queue length and the hop-count from source node to destination node. Then we present the GRA-AODV routing protocol based on the gray relevance algorithm. By comparing the simulation and experimental results, in the case of slightly increase in routing overhead, the improved Gray Relevance Algorithm-AODV routing possesses lower average end to end delay and lower packet loss rate, and it has superior robustness in the mobile Ad Hoc Network with network topology changing frequently.