Abstract: A novel detection algorithm of follower noise jamming for Frequency Hopping (FH) communication system was proposed based on the Cognitive Radio(CR). The detection performance of single hop was researched using the energy detection algorithm. Then the detection of follower noise jamming was realized in the data fusion center using the “k out of n” rule, the detection performance of follower noise jamming was deducted in additive white gaussian noise (AWGN) channel. The results analyzing and simulation show that the detection probability of single hop and Follower noise jamming(FNJ) were increased when the SINR was decreased. The detection probability of FNJ was more increased than the single hop when they were had the same SINR.