The objective of this study is to find effective and economical cement grout system for preventing corrosive gas. In this paper, in order to resist the corrosion of the cement sheath by acid gas, a new corrosion resistant agent denoted as FH-1 has been added into the cement grout. A series of cement blocks formed by cement system with different additives quantities have been obtained. The permeability, compression strength and corroding depth of these cement blocks have been investigated. The microstructure of cement blocks has been analyzed by scanning electron microscope (SEM) and the mechanism of corrosion resistant of FH-1 has been discussed. The FH-1 shows excellent resistance to corrosion against CO2, and H2S gas.Therefore the optimal corrosion resistant cement grout systems were obtained.