Abstract： The detection performance of follower noise jamming (FNJ) for frequency hopping(FH) communication was analyzed in the Rayleigh fading channel. The detection performance of single hop was studied in the AWGN (Addive White Gaussian Noise) channel using the cooperative spectrum sensing in cognitive radio (CR). The detection probability and false alarm probability in the Rayleigh fading channel were deducted. Besides, the detection performance of FNJ in the Rayleigh fading channel was obtained using the “k out of n” rule. The simulation valified the results of theoretical analysis.