The submodule capacitor voltages in modular multilevel converters(MMC) must be maintained at their nominal values to ensure reliable operation. Traditional methods for capacitor voltage control(including averaging control, arm-balancing control, and individual-balancing control) exhibit limitations of nonlinear controlled plants and strong coupling between different closed loops, which complicates controller design and hampers the enhancement of dynamic performance. This paper proposed a series of linearized control methods for the submodule capacitor voltage control of MMCs. With these methods, the transfer function of each closed-loop controlled plant becomes a pure integrator, thereby simplifying the controller design process. The efficacy of the proposed control methods is validated through experimental results obtained from a downscaled MMC prototype.