Abstract: The invention discloses a special-purpose reactive disperse dye for waterless dyeing of natural fibers in supercritical CO2 fluid and an intermediate thereof. The reactive disperse dye has a longer alkane-chain bridging group between a chromophoric parent structure and an active group of the dye, which effectively promotes the donating-withdrawing effect on the electron cloud in the conjugated system, enhances the hyperchromic effect, effectively reduce the influence of the active group itself and its reaction on the dye coloring system, improves the color and stability against acid and alkali of the dye, and facilitate the improvement of the compatibility of the dye with supercritical fluid and the dyeing performance for natural fibers as well. The invention also discloses an intermediate of the reactive disperse dye, and a method for preparing the reactive disperse dye.