Abstract: Corrosion of casing greatly restricts the development of Zhongyuan Oilfield.It is concluded that inner corrosion is serious in the water wells of the oilfield,as well as sulfate reducing bacteria(SRB) is the main factor of corrosion based on the investigation of casing corrosion and the research on corrosion mechanism.Inner corrosion of oil well casing is not very serious,of which HCO3-is the main factor that causes the corrosion.In view of the causes of internal and external corrosion of casing,the inner corrosion control technology is developed.Effective GHJ corrosion inhibitor of oil wells and solid corrosion inhibitor are developed to deal with the corrosion of oil wells casing.And the periodic technology of washing wells with high ph value injection water and two types of annulus protection fluid XHK-1 and XHK-2 are developed to deal with the inner corrosion of injection wells casing.On-site application shows that the control technology effectively slows down the carrion rate of oil-water wells and improves the conditions of oil-water wells.Great economic benefits and social results are obtained.