The invention discloses a GMSK signal receiving method in satellite mobile communication. The method comprises that firstly, double-Chirp signal assistance is conducted to perform system synchronization, by the aid of the method, the Doppler frequency and the time delay existing in a satellite mobile channel can be estimated quickly and accurately, and the system synchronization can be achieved; on the basis of completion of the system synchronization, a quasi-coherent algorithm is used for performing GMSK signal demodulation, according to the method, before the GMSK demodulation is performed at a transmitting end, 'precoding' is performed on raw information, and meanwhile, a 'de-rotation' module is added at a receiving end to simplify the design of timing synchronization greatly. The method is low in implementation complexity and low in performance loss. Performance test results of hardware implementation indicate that the relative loss of the bit error rate (BER) performance of the GMSK receiving method to the binary phase shift keying (BPSK) optimal coherent detection performance is about 0.7-0.8dB.