In this paper, Atmospheric channel model is established while beam expander loss, mismatch loss, atmospheric attenuation, turbulence effects and thermal noise are comprehensively considered. Low density parity check (LDPC) codes are applied for error control. Based on the concepts of complete system of residues system in algebraic member theory, H matrix eliminated four-rings is constructed. Entire system is established, and LDPC codes encoding were completed by approximate lower triangular matrix encoding algorithm while decoding is based on probability decoding algorithm with posterior probability provided from communication channel. The simulation result shows that the wireless laser transmission is accurate and reliable and LDPC coding makes the performance improved by 2∼3 dB.