Abstract: The Dalaoba condensate gas reservoir belongs to the deep condensate gas reservoir with edge water of high temperature and pressure, high wax content and condensate content. During the process of depletion deve-lopment, retrograde condensation and water invasion often occur, resulting in the sharp decline of gas well productivity. Cyclic gas injection is applied to enhance gas reservoir recovery. Since cyclic gas injection was carried out during the middle-later period of the reservoir's development, for ensuring cyclic gas injection's recovery efficiency and economic benefit, the relationship was analyzed through simulation method between condensate content changes and cumulative oil and gas output after implementing gas injection for water-drive condensate gas reservoir, such as Dalaoba condensate gas reservoir. It was determined that condensate oil content would drop to 100 g/m³ in 2029, and the cumulative volume of gas injection would reach 24.65×10⁸ m³ at that time. The exploitable geological reserves would be optimized under economic condition, thus ensuring the development effect of cyclic gas injection.