With the continuous development of the oilfield, it has entered a phase of medium to high water cut, facing the problems of long service cycle of the casing, aggravated corrosion, increasing severity of casing damage, deterioration of the effect of isolation production management year by year, and no breakthrough in the long-term management process, etc. It is urgent to analyze and deepen the reasons for constraints and implement precise measures. In this paper, through sorting out the technical difficulties of small casing restoration, combining the effect of small casing restoration in the previous period and the influencing factors, formulating technical countermeasures for the main technical constraints of small casing restoration, and carrying out the optimization of small casing restoration process and technology and feasibility study in terms of optimizing the optimization of reservoir leakage prevention and protection and optimizing the optimization of reservoir modification. The casing restoration technology system of “narrowing the sealing radius, cementing low-density and high-strength cementing, and small displacement pre-acid fracturing” has been established in Suijing Oilfield to reshape the integrity of the wellbore, and the management system is being evaluated in terms of the on-site application effect. The results showed that by optimizing and adjusting the small casing restoration technology, the construction success rate and capacity recovery rate were greatly improved. This effectively solved the problem of low capacity recovery after small casing cementing treatment of casing damage wells and improved the effect of long-term casing damage treatment. It provides strong technical support for the next improvement measures and Suijing Oilfield’s old wells to increase the potential and efficiency and casing damage wells treatment.