In the present study, synthesis of graphene/polysiloxane (PSX) nanocomposite films possessing dual function, high electrical conductivity and superior corrosion protection, was investigated. Bar coating using a metering rod was selected as a facile coating method to facilitate in-plane ordering of filler networks in the barrier film. With complementary effects between inorganic polymer matrix as the main defensive layer and covering agent of graphene defects and, graphene as the conducive filler and relaxation agent against unavoidable stress during construction of the polymer barrier matrix, PSX-G composite coating films showed decreased rates of corrosion (1/40th), dramatic improvement in charge transfer resistance (20,000%) compared to uncoated metal substrate, and the addition of electrical conductivity (1700 S m(-1)). This system has the potential to be applied to industrial fields (e.g., anti-icing, electromagnetic shielding (EMI), and energy storage systems), which require dual functions of durability from corrosive environments and high electrical conductivity.