Based on the characteristics of follower jamming which changes frequency with the communication signal, a method to detect follower jamming is proposed. The method uses the energy detection approach to detect the unused channel and detect the communication channel by inserting a training sequence into the signal. According to whether the jamming continuously appears or disappears with the communication signal many times, it can judge whether the system is subjected to follower jamming. In addition，the detection probability in Additive White Gaussian Noise(AWGN) channel is derived. Through the computer simulation of the proposed method, the detection probability under different simulation conditions is calculated，which verifies the correctness and effectiveness of the method. The theoretical analysis and simulation results show that the more number of channel changes, the higher credibility of the test result, but the lower detection probability. Under the condition of low signal-to-jamming ratio, the simulation detection probability is consistent with the theoretical value，and the detection performance is greatly affected by the channel noise under the condition of high signal-to-jamming ratio.