The invention discloses a mosquito repellent liquid, comprising the following ingredients: 10-25 weight portions of lavender, 35-50 weight portions of lemongrass, 8-20 weight portions of aloe, 8-15 weight portions of calendula, 10-20 weight portions of chamomile, 25-40 weight portions of jasmine, 10-20 weight portions of rose, 35-50 weight portions of cordate telosma, 35-50 weight portions of mint leaves, 35-55 weight portions of camphor leaves, 20-40 weight portions of wormwood, 20-40 weight portions of eucalyptus leaves, 10-20 weight portions of star anise, 20-40 weight portions of Lantana camara, 15-35 weight portions of Mozzie buster, 10-20 weight portions of Salvia officinalis, 10-20 weight portions of marjoram, and 10-18 weight portions of rosemary. The preparation method comprises the following steps: weighing and mixing the raw materials according to the weight proportions, immersing the raw material mixture in ethanol having 15-30 times the weight of the mixture for 20-35 h, filtering, and filling. The mosquito repellent liquid disclosed herein contains no chemical additives, can effectively protect skin from being bitten by mosquito, and has the effects of removing miliaria, relieving itching, reducing swelling, relieving pain, refreshing mind, restoring consciousness, purifying air, resisting inflammation, and sterilizing.