The invention provides a joint LDPC encoding recursive MSK modulation and demodulation system, which comprises a transmitting end and a receiving end. The transmitting end comprises an LDPC external encoder and a recursive MSK modulator, and the receiving end comprises a quadrature down conversion and low-pass filter, a coarse carrier frequency offset estimation module, a buffer, a demodulation selector, an MSK differential demodulator, an N frame synchronization head-related detector, an MSK coherent demodulator, a carrier and timing synchronization processing module, a parallel/series conversion module and an LDPC decoder. The invention completely eliminates the performance loss caused by MSK differential encoding by fully integrating the recursive MSK differential encoding part into LDPC codes, fully utilizes the characteristic that the recursive MSK can carry out the differential demodulation, rapidly realizes the detection of frame synchronization head sequence of the LDPC codes under the premise of having no need of precise carrier synchronization, further switches to the MSK coherent demodulation, carries out synchronization and LDPC decoding and realizes the functions of rapid demodulation and decoding.