The atmospheric laser communication channel model is established,and the recognition algorithm formula of LDPC codes in atmosphe ric laser communication channel is proposed by using the received posterior probability information in the soft decision sequence and combining with the atmospheric laser communication special modulation.The simul ation results show that when the correct recognition rate is 0.8,under the condition of strong turbulence,the performance of the proposed algorithm is improved by about 1.2dB compared with that of traditional algorithm;and under the condition of weak turbulence,the pe rformance of the proposed algorithm is improved by about 1.5dB compared with th at of traditional algorithm.Besides,when the code rate gets lower,and the code l ength gets larger,the correct recognition rate gets higher.