The invention provides a mosquito repellent liquid. The mosquito repellent liquid comprises, by weight, 10 to 25 parts of 
lavender, 35 to 50 parts of lemon grass, 8 to 20 parts of aloe, 8 to 15 parts of 
calendula officinalis, 20 to 40 parts of argy wormwood, 20 to 40 parts of 
lantana camara L, 15 to 35 parts of 
pelargonium graveolens, 5 to 20 parts of 
agastache rugosus, 5 to 20 parts of clove, 5 to 15 parts of radix angelicae, 5 to 10 parts of folium perillae, 5 to 10 parts of Chinese prickly ash, and 5 to 20 parts of 
ailanthus altissima 
skin extracted solution. A preparation method comprises following steps: the above raw materials are mixed so as to obtain a mixed 
raw material; the mixed 
raw material is immersed in 
ethanol for 35 to 55 h, wherein the weight amount of the 
ethanol is 30 to 50 times of that of the mixed 
raw material; filtering is carried out, and an obtained filtrate is subjected to filling; 5 to 20 parts of 
ailanthus altissima 
skin extracted solution is added into the filtrate, and an obtained product is stirred to be uniform so as to obtain the mosquito repellent liquid finished product. The mosquito repellent liquid contains no chemical additive, is capable of protecting 
skin from mosquito, dispelling miliaria and relieving 
itching, relieving swelling and pain, refreshing oneself and restoring 
consciousness, purifying the air, and diminishing 
inflammation and sterilizing.