Abstract: To overcome the shortcomings of conventional 400 Hz intermediate-frequency power supplies, such as complex topology structures and large volumes, we use a Buck-Boost matrix converter (BBMC) as its power conversion circuit and propose its corresponding control and parameter optimization methods. First, we introduce the topological structure and basic working principle of BBMC and establish a mathematical model of the BBMC. Second, combined with the control requirements of a 400 Hz intermediate-frequency power supply, we propose a double closed-loop control strategy based on quasi-proportional-resonance control and thoroughly study its specific design Keywords method. Third, we propose a salp swarm algorithm to optimize its control parameters. Finally, the control effect of the proposed method is simulated and verified experimentally, and the proposed method is compared with a conventional compound control strategy based on repetitive control. Experimental results show that the application of BBMC to a 400 Hz intermediate-frequency power supply effectively reduces the volume and weight of the power supply device. Moreover, the proposed control and parameter optimization method has better steady-state and dynamic performance than the conventional compound control method based on repetitive control; therefore, it has better application value.