In China, silk relics have been excavated in large quantity and variety; however, because of the relative high humidity of the burial environment, some silk relics were even soaked in the liquid in the coffin, and a lot of crystals formed on their surfaces, affecting their quality. Therefore, the cleaning of such silk is an important part of heritage conservation. In this study, crystal fouling on the surface of silk relics from the Tang Dynasty was analyzed using Raman spectroscopy and X-ray diffraction. The results showed that the main component of the crystals was CaSO4[middle dot]2H2O. Kombucha fermentation solution was found, under microscopic observation, to cause no damage to the silk, and the silk passed the tension strength test. Because of its biological acid and enzyme content, Kombucha fermentation solution could be used to remove the crystal fouling on the surface of silk relics. A good cleaning effect was achieved without damaging the silk.