Abstract: The iterative channel decoder of joint source-channel decode has the transform of log-likelihood and probability, also the multiplication and accumulation operation, which improves the computation complexity of channel decoder. In order to reduce the complexity, this paper proposes the simplified iterative channel decoding algorithm. The algorithm directly utilizes the hard decided value of channel decoder and parameter prior probability to estimate the extrinsic information for iterative channel decoder. Based on Gaussian-Markov source, simulation results show that the simplified iterative channel decoder significantly improves SNR of received parameters and reduces the computation compared with separation source channel decoder. Also, the simplified algorithm does not degrade the performance of joint source channel decoding algorithm obviously.