Based on the mapping relationship of “flux-inductance”, the equivalent circuit of zero-mode inrush current is used to explain the physical mechanism of the zero-mode inrush current characteristics of high-impedance transformers (including the type of high-voltage winding built-in and the type of low-voltage winding series inductance) and traditional transformer. The physical models of two high-impedance transformers and traditional transformer are designed and manufactured with reference to the actual transformers, and a dynamic simulation test system is constructed. Based on the test waveforms, the effects of factors such as remanence (opening angle), closing angle, voltage, secondary winding connection mode, and transformer type on the characteristics of the zero-mode inrush current are analyzed and compared, and the correctness of the physical mechanism is verified. In order to resist the risk of zero-sequence protection misoperation caused by zero-mode inrush current of high impedance transformers, methods such as moving the tap-changing windings inside, matching opening and closing angle, and second harmonic restraint are proposed. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900600) and Science and Technology Project of Guangdong Power Grid Co., Ltd. (No. GDKJXM20162461).