Reactive dyeing of paper yarn with bifunctional reactive dyes (Reactive Red R-2BF, Reactive Yellow R-4RFN, and Reactive Blue R-2R) is carried out. The effects of process parameters such as dye concentration, dyeing temperature, dyeing time, and concentrations of sodium sulfate and sodium carbonate on the dyeing results are investigated. The results indicate that at 4.0% of dyes, three reactive dyeings exhibit the best dyeing performance. The optimal conditions for Reactive Red R-2BF are dyeing at 60 ℃ for 55 min, with both sodium sulfate and sodium carbonate concentration of 30 g/L; for Reactive Yellow R-4RFN are dyeing at 60 ℃ for 50 min, with sodium sulfate at 40 g/L and sodium carbonate at 30 g/L; and for Reactive Blue R-2R are dyeing at 60 ℃ for 60 min, with both sodium sulfate and sodium carbonate concentrations at 40 g/L. Under optimized process conditions, as the dye concentration increases, the lightness (L value) of the paper yarn significantly decreases while the color depth (K/Svalue) continuously increases. The color fastnesses to rubbing and soaping are above Grade 4.