pH value of fluorescent ink-jet ink has an obvious influence on fluorescent powder, high or low pH value could cause some problems, such as fluorescence quenches, fluorescent quantum yield decreased, and so on. And these factors make against fluorescent ink-jet ink luminous properties reach the best result. This article is to design fluorescent ink-jet ink formula when it is exposured to deep Ultraviolet light to display green, and a series of ink samples were prepared. pH regulator was used to regulate pH value of green fluorescent ink-jet ink system. This paper discusses the effects of pH value on luminous intensity, fluorescent quantum yield. The results indicated that triethanolamine can regulate pH value of fluorescent ink-jet ink, when pH value increases from 8.70 to 11.20, luminous intensity, fluorescent quantum yield have a decrease tendency.