Abstract: The low ripple adjustable DC regulated power supply based on Buck-Boost inverter circuit is a new type of power supply structure with simple structure and series advantages. However, its output DC voltage ripple coefficient and efficiency are greatly affected by the power switching frequency in its inverter circuit. Therefore, we propose a power switching frequency optimization method based on exponential distribution optimization algorithm. Firstly, we describe the transient process of its power switch and the calculation method of its loss power, analyze the influence of its power switching frequency on its output DC voltage ripple coefficient and efficiency, and establish the relevant mathematical model. Secondly, on this basis, we propose an exponential distribution optimization algorithm to optimize its power switching frequency, and then study and determine the functional relationship between its optimal power switching frequency and its output DC voltage. Finally, the above theoretical research is verified by simulation and experiment. The results show that the power switching frequency optimization method proposed in this paper for the new power supply structure effectively reduces the output DC voltage ripple coefficient and improves its operating efficiency, thus achieving better optimization results.