The use of biogas as an environmental gas modulator to preserve and store apples is a practical technique with less investment, simple operation, and significant benefits. First, the mechanism of marsh storage Apple preservation of the most critical issue is to try to inhibit Apple's breathing intensity, reduce the consumption of apple sugar and water, to achieve the purpose of safe storage. The main component of biogas is methane, which accounts for about 60% to 75% of biogas. Followed by carbon dioxide, accounting for about 20% to 25%. The use of methane and carbon dioxide in biogas is extremely high and harmless to apples, as a component of the gas in the storage environment, resulting in a certain state of hypoxia, effectively inhibiting the respiratory intensity of apple and sugar transformation, extending the shelf life. The results showed that: Compared with ordinary bag storage (control), the marsh storage has a high hardness of 0.32 to 0.33 kg/cm2, a sugar content of 0.72 to 2%, a water consumption of 0.3 to 1.8%, a high fruit rate of 13.6 to 15.1%, and a taste it is good. The fruit storage time is more than 200 days. Second, the marsh storage method 1, fruit picking: In the apple before the onset of respiratory intensity (usually in mid-October) for fruit picking, and pre-cooled about 3 days, so that Apple's field heat loss. 2. Packing fruit: Put the good fruits without damage and without damage into the storage room sealed with polyethylene film, and then close the door. 3. A gas meter is used to quantitatively charge the biogas into the storage room. Each day cubic meters of storage capacity of 0.05 ~ 0.07 cubic meters of biogas, every 10 days, every cubic meter of storage capacity of biogas to increase to 0.12 ~ 0.16 cubic meters. 4, temperature and humidity control: Under normal circumstances, according to different species storage room temperature should be maintained at 1 ~ 5 °C, humidity should be stable in the range of 80% to 90%. The deviation above and below the temperature should be less than 1°C and the humidity should be less than 5%. 5. Routine management: In the first two months after the storage room is filled with biogas, the storage fruit is turned once every 10 days, and then it is turned once a month and ventilation is performed. Ventilation time is generally low temperature season should be between 10 am and 4 pm on the same day. Ventilation should be carried out at night when the temperature is high. Biogas preservation and storage of apples are significantly better than ordinary bagged fruit preserves regardless of good fruit rate, apple sugar content, hardness, or apple appearance, color, and cleanliness. Using this method to preserve fresh apples, the cost is low, the method is simple, and the benefits are high. The people are happy to accept it.