Design optical communication coding schemes under time-varying channels to promote optical communication technology in reducing inter symbol interference and channel distortion in complex and changing channel environments, achieving more efficient and stable data transmission. Construct a time-varying optical communication channel model that considers factors such as multipath effects, nonlinear distortion, signal attenuation, and noise, and introduce direct sequence spread spectrum (DSSS) technology and parameterized inverse time matrix (PTRM) technology to mitigate inter symbol interference and channel distortion; At the transmitting end of optical communication, an optical communication encoding scheme was designed using low-density parity check (LDPC) encoding technology. By constructing a sparse parity check matrix and using the row column permutation algorithm (RU algorithm) to convert the parity check matrix into an approximate lower triangular form, an LDPC encoded codeword vector was generated; At the receiving end, a soft decision decoding method is used to gradually approximate and determine the transmission codeword through fine multi-level quantization processing and iterative algorithms. The experimental results show that under different temperature fluctuations and signal-to-noise ratio conditions, this encoding scheme can significantly reduce the bit error rate.