Abstract: The gate driver, serving as the bridge connecting low-voltage control circuit and high-voltage power circuit, ensures the reliable switching of power electronic devices, but it also suffers from intense electromagnetic interference (EMI). Existing researches on conducted EMI in gate drivers focus on differential-mode (DM) interference represented by "crosstalk", while lacking in in-depth analysis of common-mode (CM) interference. CM interference is the major interference source for gate drivers because of its numerous propagation paths, wide frequency range and extensive influence. To address the limitations of existing researches, this paper concentrates on the high-frequency (HF) characteristics and analyzes the CM interference characteristics of gate drivers. Focusing on switching voltage overshoot and HF oscillations, trapezoidal waveform with attenuated sinusoidal waveform is used to model the interference source. Based on the converter and gate driver architecture, the multi-branch coupling network of CM interference is built layer by layer and its wide-band impedance characteristics are analyzed. The CM current and the drive signal interference voltage are selected as the targets, whose transfer functions are solved and the failure mechanisms are analyzed in conjunction with the source characteristics. Experimental results show that the HF oscillation of the source will generate serious interference. When the oscillation frequency of the source is the same as the resonance frequency of the coupling network, the CM interference will be enlarged. Extra attention needs to be paid in the gate driver design. This paper concludes with a guide to the anti-jamming design of gate drivers at the theoretical level based on the EMI model developed.