The number of sub-modules in the MMC system is large, and in the operating state, the sub-module floating ground voltage generates high dv/dt along with the sub-module switching, which will cause EMI issues in the sub-module itself such as driver interference due to the existence of circuit parasitic parameters. In this paper, a driver interference model is established, a sub-module interference source model is built and simplified, and the sub-module power device driver loop is modeled and equivalent. the model is verified by simulation, and the influence of different parameters on the interference is analyzed.