Abstract: In order to deal with the reduced fluorescent effect of fluorescent acrylic yarn after dyeing with common process, the fluorescent acrylic yarn was taken as the main research object. The influence of dyeing process factor, homochromy dyeing of tri-chromatic dyes and adding fluorescent whitening agents on the fluorescent effect of yarn was analyzed. The optimum dyeing process of fluorescent acrylic fiber was obtained by testing fluorescent reflectivity as follows: dyeing at 85℃ for 75 min with pH value = 3.5. In addition, the relationship between dyeing process and fluorescent property of fluorescent acrylic yarn was studied by analyzing its fluorescent spectra. The result showed that fluorescent acrylic yarn dyed with optimum process and appropriate dyes has favorable fluorescent effect. Fluorescent whitening agent can further improve the fluorescent effect during the combination dyeing process with Fluorescent Yellow 10GFF or Brilliant Red X-5GN.