Abstract: According to serial concatenated convolutional codes(SCCC) adaptive coded modulation scheme defined in the consultative committee for space data systems (CCSDS) standard, Log-MAP algorithm and Max-Log-MAP algorithm with multiplicative correction were analyzed and compared in the decoding performance and implementation complexity. On the basis of these studies, a parallel decoding method with low complexity and high coding gain was proposed in this paper. Furthermore, a general and parallel decoding structure, supporting a variety of coded modulation schemes, was provided. Finally, based on FPGA hardware platform, a high-speed, parallel and high-throughput SCCC decoder was designed for eight coded modulation schemes. The testing result indicates that the maximum throughput can be up to 300 Mbit/s.