Abstract: In order to study the influence of driving parameters on the electromagnetic transient process and electromagnetic disturbance characteristics of the Module Multilevel Converter（MMC） in normal operation, a sub-module transient model of MMC was established. By means of mechanism derivation and electrical equivalence, the model reflects the influence of driving parameters on the rate of change of voltage and current and simulates the transient characteristics of voltage and current overshoot. The validity of the model was verified by comparing with the actual MMC sub-module double pulse test. In addition, the influence law of driving resistance R_G, gate inductor L_G and emitter inductor L_E on electromagnetic disturbance source was obtained through mechanism derivation and simulation analysis, which is beneficial to further apply the model to the simulation of flexible DC transmission system and evaluate the electromagnetic disturbance level of the actual converter.