The invention discloses a method for allocating frequency spectrum resources based on honest cooperation in a composite cognitive radio network, which comprises the allocation processes: firstly, access networks estimate respective minimum bandwidth demands and inform a network reconfiguration manager of the minimum bandwidth demands; secondly, the network reconfiguration manager dynamically allocate the frequency spectrum resources to the access networks according to a cooperative game model and a Nash bargaining method; thirdly, the network reconfiguration manager calculates utility loss brought by one access network in all the access networks to the other networks in sequence, takes the utility loss as a cost factor of the access network and calculates the cost required to be paid by the access network; and fourthly, the network reconfiguration manager respectively transmit the allocated frequency spectrum resources and the cost to the access networks. The invention not only can effectively encourage the access networks to honestly put forward the minimum bandwidth demands, remit the situation of excessive use of the frequency spectrum resources at pains on the basis of satisfying the frequency spectrum demands of each access network, improve the whole utility of all the access networks, but also can be used for dynamically allocating the frequency spectrum resources in the composite cognitive radio network.