A gate voltage magnitude compensation equalization method and circuit for series operation of power switch transistors are provided. A dynamic voltage equalization of series-connected power switch transistors is implemented by using sampling principles where voltages of the power switch transistors are controlled by gate voltage magnitude and unbalanced voltage differentials are converted into unbalanced current differentials of buffer currents. The gate voltage magnitude compensation equalization method and circuit relates to differential control and works in a dynamic voltage change process of the series-connected power switch transistors, without having a negative effect on operation of the power switch transistors under normal operating conditions. Only adopting passive devices, the gate voltage magnitude compensation equalization circuit has a simple structure, is easy to integrate on a device drive board, implements response tracking of unbalanced voltage and voltage equalization of the series-connected power switch transistors, and improve speedability and stability of voltage equalization control.