Abstract: How to realize the cognitive capability is a key point to realize the cognitive wireless network. At present the method that combines network situation-aware database with case based reasoning (CBR) is received much attention. The construction of database in cognitive wireless network based on network situation-aware is deeply investigated in unfixed establishment network such as Ad hoc. The combination of NSGA-Ⅱand fuzzy decision is applied to constructing the Database in Cognitive Wireless Network from the aspect of network situation-aware and protocol configuration. Simulation result shows that: when adopting the mechanism of reconfiguration, the average time delay of the network will decrease to 50% above that of worst performance; the ratio of calling success will increase to 100%, and the throughput of the network will increase to 20%.