Abstract: Aimed at the problems of signal attenuation and fading caused by absorption, scattering and turbulence in high-speed underwater visible light data transmission, a beamforming algorithm based on maximum ratio combination for the underwater communication is proposed. Through space diversity, the received signals were combined through different paths, and the beamforming optimization model with the goal of maximizing the signal-to-noise ratio was established. Under the constraints of the non-negative optical signal and the total power, the optimal beamforming vector was solved to form the target beam with the largest SNR, and overcome the influence of turbulence. The simulation results show that under the influence of weak and strong turbulence, when the bit error rate of 10-6, in the visible light MIMO communication systems of 2×2 and 4×4, respectively, the proposed algorithm achieves 2.2dB, 1.8dB and 2.2dB, 5dB SNR.