Due to the multipath effect and time-varying effect of underwater channel, the underwater radio communication rate and signal-to-noise ratio are very low. In the actual underwater communication application scenario such as underwater sensor network, it is necessary to obtain the code stream signals of multiple signal sources at the same time. An underwater visible multi input multi output(MIMO) communication system based on CMOS camera is proposed. The system samples Manchester code to recover the clock signal of different distance signal sources. At the same time, the method of multiple signal sources identification and light intensity fitting is proposed. The influence of baud rate on the signal waveform distortion in underwater environment is explored. The experimental results show that the system can achieve 21 kb/s underwater communication after the LED array is optimally arranged in a 4 m×3 m×3 m test cell. It can be used in short distance and small information data exchange occasions such as underwater sensor network.