In order to provide safer and safer water, it is necessary not only to filter and disinfect chlorine, but also to inactivate chlorine resistant bacteria (Cryptosporidium, etc.) by ultraviolet rays. At present, high power ultraviolet mercury lamp has been widely used in this field. However, as mercury is toxic to human body and harmful to environment, more environmentally friendly light sources are needed. Deep UV LED, can realize mercury free, can provide safer, safer water sterilization technology. In addition, due to the long service life at the same time, the use of deep UV LED also helps to reduce the use of environmental resources.