The influence of atmospheric turbulence on wireless optical communication systems cannot be ignored. In order to accurately reflect the actual features of laboratory-simulated multiple-input multiple-output (MIMO) atmospheric turbulence channels, a method using phase screens to simulate MIMO atmospheric turbulence channels was proposed. The liquid crystal modulation method based on liquid crystal spatial light modulator (LC-SLM) was studied, and the feasibility of the method was verified by experiments. The experimental results show that the laser spot of MIMO atmospheric turbulence channels simulated by phase screen has different degrees of distortion. In the turbulent environment, the power stability of the two-channel laser emission system is better than that of the single-channel laser emission system. Under the forward error correction error limit (3.8×10^-3), the link penalty of the single-emission single-receiving system is 10.5 dB, and the link penalty of the two-emission two-receiving MIMO system is 9.3 dB. This research provides a new idea for the experimental method of simulating MIMO atmospheric turbulent channels in laboratory.