Abstract: In order to improve auction effectiveness in dynamic spectrum assignment(DSA), a new assignment scheme based on FADM(fast auction with multiple goods and multiple winners) algorithm was given. The FADM algorithm transforms the traditional multiple goods auction into an integer 0/1 knapsack problem, whereby the optimal clearing vector can be found with dynamic programming. Our scheme restrains collusion with reservation price and discriminated price. Furthermore, the reservation price and bid price can be adjusted dynamically to spectrum supply and demand, which can balance revenue and social efficiency of spectrum auction. The results of performance analysis and simulation indicate that the FADM algorithm can make spectrum utilization close to demand and improve allocation revenue as high as possible.