针对连续变量量子密钥分发(CVQKD)通信距离较短的问题,在多维数据协调方案的基础上,利用连续密度进化和差分进化方法,设计出优质度数分布的低密度奇偶校验(LDPC)码,并提出LDPC码码字重复方法,进一步提高多维数据协调的效率,有效地降低了收敛信噪比,延长了信息传输距离。实验仿真结果表明:在分组码长为106时,收敛信噪比能够降低至-6dB以下,协调效率可达90.27%,提取到的安全密钥量为0.22kb/s,信息传输距离超过80km,该方法可有效延长CVQKD系统的通信距离。 Aiming at the short communication distance of continuous variable quantum key distribution (CVQKD), on the basis of multi-dimensional data reconciliation scheme, a high-quality low density parity check (LDPC) code is designed by using continuous density evolution and differential evolution , And proposes the LDPC code word repetition method to further improve the coordination efficiency of multi-dimensional data, effectively reducing the convergent signal to noise ratio and extending the information transmission distance. The simulation results show that the convergence SNR can be reduced to below -6dB and the coordination efficiency can reach 90.27% when the packet code length is 106, the extracted security key is 0.22kb / s, the information transmission distance is over 80km, This method can effectively extend the communication distance of CVQKD system.