The moisture retention agent uses a highly absorbent resin, a functional polymer material with exceptional water absorption capabilities. It is non-toxic and harmless, capable of repeatedly releasing and absorbing water, thus likened to a "micro-reservoir" in agriculture. Additionally, it can absorb fertilizers and release them slowly, enhancing fertilizer effectiveness. High absorbent resins are widely used in agriculture, forestry, horticulture, building materials; in industry, they are extensively applied in petrochemicals, cables, papermaking, sensors, fire extinguishers, fiber products, cosmetics, food preservation, and expandable toys.