Abstract: To study the influencing factors and application conditions of UVC LED sterilization ability, Escherichia coli was sterilized by UVC LED at different exposure times and exposure distances, and the sterilization rate was calculated. The experiment results indicate that the sterilization ability of UVC LED decreases exponentially with the decrease of UV dose, which is affected by UV radiation flux, exposure time and exposure distance. Taking the experimental light source as an example, when the ratio of the exposure time to the square of the exposure distance is more than 20/10^-2 s/cm², the sterilization rate of the UVC LED can reach more than 99%. UVC LED can not sterilize by generating ozone, therefore it is only suitable for surface sterilization. Through empirical formula, the application conditions can be estimated. Based on these conclusions, a UVC LED sterilization lamp prototype was designed and produced.