To inhibit the corrosion of low alloy steel in marine atmospheric environment, the bacteria induced mineralization was used to prepare a bimineralized film on steel surface. In this paper, a novel and “green” approach was applied for protecting steel by a marine bacterium Pseudoalteromonas lipolytica. This approach protects steel from corrosion in the marine atmospheric environment via the formation of an organic-inorganic hybrid film, which is composed of calcite and extracellular polymeric substances. The corrosion resistance of the biomineralized film in a thin electrolyte layer was studied by the Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization and Kelvin probe technique. The morphology and composition of the biomineralized film were analyzed by SEM, FTIR and 3D optical profilometer. The most corrosive 50 μm thin electrolyte layer was chosen for the test for 30 d. After 24 d, the biomineralized film exhibited a good corrosion inhibition, which was observed by the 3D optical profilometer. Moreover, SKP test showed the voltaic potential kept stable, only decreasing from –0.16 V to –0.2 V. However, the corrosion occurred on steel surface as well as voltaic potential decreased from –0.20 V to –0.45 V after 30 d, indicating that the corrosion protection of biomineralized film decreased. In addition, the salt spray test images showed signs of corrosion after 24 d, resulted from the damage of the biomineralized film. The result was confirmed by the FTIR, in which the vibrational peak value of organics in biomineralized film decreased. Therefore, this study indicates that he biomineralized film can protect the metal from corrosion in the first 24 d under the immersion of thin electrolyte layer. After immersion for 30 d, due to the dissolution of organic matter in the biomineralized film, the mineralized film has defects and cannot avoid the permeation of the corrosive medium. In the future, the lasting and the compact of the biomineralized film should be further improved for real application.