The invention discloses an externally used Chinese medicine preparation for curing viral dermatoses and a preparation method. The externally used Chinese medicine preparation includes, by mass, 40-45% of bitter gynostemma pentaphyllum, 18-23% of sophora flavescens, 18-23% of barbed skullcap herb, 1-1.5% of borneol, 2-3% of azone and 20-25% of ethanol. The sum of mass percentages of all components is 100%. The preparation method includes weighing the gynostemma pentaphyllum, the sophora flavescens and the barbed skullcap herb, adding water, decocting, filtering and removing slag, and performing concentration; adding 95% of ethanol, performing cold storage and standing, and filtering; recycling the ethanol and performing concentration; and adjusting ethanol content of the solution and adding the borneol and the azone to obtain the finished product. The externally used Chinese medicine preparation is rich in medical herb resource, safe and non-toxic, convenient to use and wide in application range, and has good development prospect. More than 20 years of clinical applications prove that the externally used Chinese medicine preparation has good therapeutic effects on viral dermatoses such as herpes zoster, varicella, prurigo, pompholyx, condyloma acuminatum and genital herpes.