ing at the problem of error diffusion in multiple-input multiple-output free-space optical (MIMO-FSO) communication system, we propose a cascaded code(LT-PC) scheme of the Luby transform (LT) code and the parity check (PC) code. The LT-PC scheme can locate and delete wrong packets by adding a checker based on LT code. The performance of the LT code is compared with that of the LT-PC code. The LT-PC code is verified by the simulation under the systems with different number of MIMO groups and communication distances. Different atmospheric turbulence intensity channels are also simulated. The results show that the LT-PC code can improve the success rate of decoding when the decoding overhead is less than 0.5. In the same turbulence environment, the system with antenna number of 3×3 has about 3 dB coding gain compared with the system with antenna number of 2×2. After using the LT-PC code, the improving range of the coding gain is 0.5 dB~2 dB when the bit error rate is about 10 ^-5. In the strong turbulence environment, the LT-PC code still has certain advantages over the LT code with the increase of the communication distance when the numbers of antennas are the same.