In this paper, we first analyze the performance of GMSK against partial-band interference in short-wave and slow-frequency hopping. Numerical simulation results show that when the value is different, the BER of the BER varies with the SIR. When is small, the BER of SFH/GMSK is smaller than that of SFH/MFSK under the same conditions. When is large, the BER of SFH/GMSK is smaller than that of SFH/BFSK, but larger than the BER of SFH/4FSK. Then we analyze the anti-multipath interference performance of GMSK in short-wave slow frequency hopping, and choose Rayleigh fading channel and Rice fading channel for simulation. The flat fading and frequency selective fading are used in Rayleigh fading channel respectively. The simulation results show that in Rayleigh multi-path fading channel, SFH/GMSK anti-multipath fading performance is better than SFH/MFSK; in Rician channel, the larger the K value is, the smaller the error rate is. Finally, three kinds of diversity combining methods are added to a frequency-selective fading SFH/GMSK short-wave channel system. The simulation results show that compared with the bit error rate of multipath channels, by combining multipaths the system performance of bit error rate can get 2dB improvement.