The invention provides an MMC converter valve submodule forward overvoltage protection circuit comprising a main function circuit and an auxiliary function circuit that are connected in parallel. In the MMC converter valve submodule forward overvoltage protection circuit provided in the invention, an electronic FOP overvoltage protection circuit in an MMC converter valve submodule can be used for accurately, timely and effectively driving bypass actions of a submodule protection device in a condition of direct current capacitor overvoltage, and the submodule can be prevented from damaged caused by overvoltage; compared with a conventional BOD hardware overvoltage protection, an FOP overvoltage protection circuit is advantaged by short time delay and small deviation value; reliable and accurate protection can be provided for safety of the submodule.