(a) Dust mite prevention: There are two main types of dust mites associated with allergies: house dust mite and dust mite. House dust mites mainly breed in the bedroom pillows, mattresses, cushions and furniture; dust mites can also breed in large numbers on the ground in flour mills, cotton mills and food warehouses, Chinese medicine warehouses and so on. Therefore, the main measures for prevention include the following: 1. Reduce the relative humidity in the room and control it below 50%. 2.Wash bed sheet, pillowcase, blanket and mattress cover with hot water equal to or higher than 55~C once a week can kill mites and remove most of the mite allergens. 3.Packing mattress pillows with special mite resistant materials is an effective way to reduce exposure to dust mites and their allergens. 4.Replacement of carpets, curtains and home decorations. 5・At a temperature of 17℃ to 2O℃. Freezing soft toys and small items (such as pillows and special clothing) for at least 24 hours is an effective way to kill mites on these items. (B) Fungus prevention: Fungus is easy to breed in damp and deciduous forests, and mostly breeds in the soil of flowers and plants, garbage cans, moldy food, unventilated bathrooms and sewer pipes, thus preventing fungus requires moving flowers and plants outside, opening windows and ventilation, and cleaning garbage in time. (C) Pollen prevention: The dispersal pattern of several major allergenic pollen is as follows: Spring is mainly elm, poplar, willow, etc., with peak dispersal in March, April and May. In autumn, pollen from grasses, artemisia, ragweed, ragweed and quinoa are predominant. Gramineae pollen has the longest dispersal time, almost all year round, but more in autumn; Artemisia pollen, quinoa and ragweed pollen dispersal peaks in August and September. If you are aware of the peak pollen season, you should minimize going outside during the peak season and wear a mask when you go out.