In the presence of sodium dodecylbenzene sulfonate (SDBS) surfactant micelles, the signal of K2Cr2O7-luminol-adenine chemiluminescence system was strongly enhanced by sodium formate, which is conventionally considered as free radical scavenger. The present article discussed the sensitizing mechanism of chemiluminescence through the methods of chemiluminescence emission spectra, UV-visible absorption spectra, and chemical reactions. The result indicated that free radical OH·, which existed in the original chemiluminescence system, was transformed into free radical O·2 by the existence of sodium formate. Based on that, a highly sensitive flow injection-chemiluminescence method to determine adenine was established. Under optimal experimental conditions, the concentration of adenine was linear with the chemiluminescence intensity in the range of 8.18×10-9 to 2.45×10-11 mol·L-1. The limit of detection (3σ) was 8.72×10-12 mol·L-1. The method has been successfully applied to the analysis of adenine in VB4 pills and the results are satisfactory.