The invention discloses a voltage balancing algorithm for a high-frequency cavity of a medical superconducting cyclotron, the invention relates to the technical field of voltage leveling, Based on thehigh frequency cavity of cyclotron in high frequency and low level system, A cyclotron high frequency cavity comprises an I cavity and an R cavity, The high-frequency and low-level system includes controller, motor driver and motor. The voltage adjusting and balancing algorithm samples the voltage of two groups of cavities in push-pull high-frequency cavity through ARM controller platform, performs a series of operations on the sampled signals, and finally obtains the trimming capacitor motor control signal for adjusting the voltage of the two groups of cavities. Under the condition of not affecting the tuning of the high frequency cavity, this algorithm has the characteristics of fast balancing speed, flexible use and high control precision, and prevents the phenomenon that the cyclotroncannot exit because of the voltage unbalance between the two groups of cavities of the push-pull high frequency cavity.