Objective To evaluate the effect of different types of ballast on radiation intensity of ultraviolet (UV) lamp. Methods UV lamps were installed on the lamp frames of electronic ballast and inductance ballast respectively, the radiation intensity of UV lamp was monitored and analyzed by ultraviolet radiation intensity monitor. Results In August 2018, at the same temperature, humidity and voltage, the average radiation intensity of 27 new UV lamps using electronic ballast and inductance ballast in a new department were (67.85±6.51) μW/cm² and (109.07±7.43) μW/cm² respectively, with the qualification rates of 0 and 100% respectively; there were significant differences in average radiation intensity and qualified rate between two groups (both P < 0.05). In October 2018, 282 UV lamps used in each ward of a hospital were all electronic ballast, with a total of 8 manufacturers; the average radiation intensity of 92 UV lamps was (103.14±22.35) μW/cm², and the average radiation intensity was (123.50±13.80) μW/cm² after replacing with inductance ballasts; difference was statistically significant before and after replacement. Conclusion The types of ballast has an effect on the radiation intensity of UV lamp, inductance ballast should be selected for UV lamp in hospital to improve the radiation intensity of UV lamp.