To meet the needs of UUV cluster collaborative communication in complex marine environments, a magnetic induction communication system based on BPSK is proposed. A channel transmission model is established to analyze the effects of different transceiver models, seawater, carrier synchronization, and carrier frequency on channel transmission, combined with MATLAB simulations and experiments for validation. Simulation results show that BPSK modulation performs well under complex channel conditions; the one-to-three receive model is insensitive to attitude changes; phase offset is a major factor in the effects of eddies, and carrier synchronization significantly reduces its impact. Ultimately, the results indicate that the bit error rate decreases to the order of 10-3, effectively meeting the collaborative communication needs of UUV clusters,validating the system′s high stability and reliability in complex marine conditions. Finally, hardware experiments further validate the feasibility of the system.