At present,the mode of appropriate disinfection technology in decentralized water supply engineering has not yet been established. To improve water quality of decentralized water supply systems,combined with pre-water treatment and ultraviolet disinfection,based on low -pressure and high intensity ultraviolet and water quality security unit (PP cotton filter and activated carbon filter),barrel-type ultraviolet disinfection device is developed in this paper. The actual application effect of barrel-type ultraviolet disinfection device is studied in a household water supply system of northern area. Results show that the barrel-type ultraviolet disinfection device can guarantee the water microbial safety effectively. The ultraviolet lamp radiated 5 min /h can kill 90 CFU/100 mL total coliforms in raw water. The barrel-type ultraviolet disinfection device has a broad application prospect with simple maintenance and low annual running cost.