Abstract:The frequency-hopping (FH) communication system has a good capability of anti-jamming. It’s easy to produce the intermodulation interference when multi-channel relay system working at FH mode. Through the use of simulated annealing algorithm for optimization, frequency assignment method for restraining the intermodulation interference of frequency-hopping (FH) communication system has been studied. By analyzing constraints of frequency assignment of frequency-hopping system, objective functions in the previous use of SA algorithm for frequency assignment have been improved. Not taking completely the probability of default as constraint weights, but strengthening the concern of intermodulation interference constraints, combined with the application background of this article, a quite good method of the frequency assignment has been received.