The results of domestic and foreign surveys so far have found that 100% of house dust contains mites, and the number of mites per gram of house dust is 10-8160, with the highest density of mites in July, August and September every year. The main conditions for their growth are suitable temperature and humidity (relative humidity 55%-85%: temperature 25-35 degrees) and human dander as food. Dust mites also family devour plant pollen and fungal spores, cells, etc. The bedroom is usually closed for a long time, the ventilation is relatively poor, and people stay for a long time, making the indoor temperature and humidity relatively higher, creating favorable conditions for dust mites to grow and reproduce, so the bedroom is the main breeding ground for dust mites, and the bedroom mattresses, sofas, bedding and pillows, and other soft and slippery facilities are subject to high frequency of human contact, high moisture production and heat production, richer amount of dander, and usually inconvenient to wash and dry, which is the main breeding ground for dust mites. The main breeding ground for dust mites.