The invention discloses traditional-Chinese-medicine mask liquid and a preparing method thereof. The traditional-Chinese-medicine mask liquid is prepared from, by weight, 25-30 parts of asiatic pennywort herbs, 12-18 parts of lawn pennywort herbs, 22-26 parts of aloe, 5-7 parts of dicranopteris pedata, 6-8 parts of blechnum orientale, 5-7 parts of ilex asprella champs, 5-9 parts of Chinese knotweed herbs, 5-7 parts of physalis alkekengi, 2-4 parts of common lophatherum herbs, 1-2 parts of radix cynanchi atrati and 5-9 parts of retinervus luffae fructus. The preparing method of the traditional-Chinese-medicine mask liquid includes the steps that asiatic pennywort herbs and lawn pennywort herbs are subjected to reflux extraction to obtain first extracting liquid; dicranopteris pedata, blechnum orientale, ilex asprella champs, Chinese knotweed herbs and common lophatherum herbs are mixed and extracted to obtain second extracting liquid; radix cynanchi atrati and towel gourds are decocted to obtain an extract, aloe and physalis alkekengi are ground to obtain slurry, and the slurry and the extract are subjected to reflux extraction to obtain third extracting liquid; the first extracting liquid, the second extracting liquid and the third extracting liquid are mixed and concentrated to obtain the traditional-Chinese-medicine mask liquid. The invention further discloses an application of the traditional-Chinese-medicine mask liquid to preparing medicine for treating acne.