The invention provides an adaptive iterative receiver in a low-density parity check code and continuous phase modulation system. The adaptive iterative receiver comprises a receiving antenna (8), a CPM (continuous phase modulation) demodulator (9), a CPM soft-input and soft-output module (10), a random deinterleaver (11), a weighted processing module (12), an LDPC (low density parity check) code soft-input and soft-output module (13), a random interleaver (2), a sign change rate judging module (14), a switching circuit (15) and a bit decision device (16). The weighted processing module (12) and the sign change rate judging module (14) are introduced and used together. Iterative times are adaptively set by the receiver according to change conditions of a Rayleigh fading channel, an iterative process is prevented from entering a positive feedback state, iterative detection is automatically stopped at a position with a small bit error rate, average iterative times are reduced, iterative detection time is saved, and convergence, reliability and instantaneity of a system are improved. In addition, the adaptive iterative receiver has the advantages of reliable performance, low complexity, easiness in maintenance and the like, and has popularization and application values in satellite communication, deep space communication and the like.