A time tester was developed to evaluate the quality of a traffic safety lighting in mesopic vision conditions. Firstly, test parameters including background brightness, visual target contrast and visual target eccentric angle were set by collecting the reaction time of human eyes to observing objects in three kinds of light sources(Light Emitting Diode/High-pressure Sodium Lamp/Metal Halide Lamp,LED/HPS/MH),and the vision efficiencies of different sources were researched.Then, utilizing the regression analysis of correlation coefficient method, the relationship between reaction time and three test parameters was obtained, respectively. Finally, based on visual performance method, the reaction time tendencies and road traffic lighting performance of the three light sources were analyzed in the mesopic vision. The experimental results show that under the same visual performance conditions, when the background brightness is less than or equal to 1.5 cd/m2, the background brightness of HPS is the maximum, MH lamps take the second place and the LEDs are the minimum. The conclusion is that the visual performance of the LEDs is better than those of other two light sources in the mesopic vision, therefore they are more suitable for road traffic safety needs.