Citric acid is a type of fruit acid, primarily used to accelerate keratinocyte renewal. It is commonly found in emulsions, creams, shampoos, whitening products, anti-aging products, and acne treatments. In chemical technology, citric acid serves as a reagent for chemical analysis, experimental reagents, chromatographic analysis reagents, and biochemical reagents. It acts as a complexing agent and masking agent and is used to prepare buffer solutions. When citric acid or citrate salts are used as washing aids, they enhance the performance of cleaning products by rapidly precipitating metal ions, preventing pollutants from re-adhering to fabrics, maintaining the necessary alkalinity for washing, dispersing and suspending dirt and ash, and improving the performance of surfactants. It is an excellent chelating agent and can be used as a reagent to test the acid resistance of architectural ceramic tiles. Citric acid-sodium citrate buffer is used in flue gas desulfurization. China is rich in coal resources, which constitute a major part of its energy supply. However, the lack of effective flue gas desulfurization processes has led to severe atmospheric SO2 pollution. Due to its low vapor pressure, non-toxicity, stable chemical properties, and high SO2 absorption rate, the citric acid-sodium citrate buffer solution is a highly promising desulfurization absorbent.