Produced by a special production process, i.e., adding a master batch online during the melt spinning process, this kind of recycled midlength polyester staple fiber comes from recycled bottle flakes, thus greatly improving its spinnability and physical specifications. With specifications of 2.2D-3D and 38mm-76m, our midlength polyester staple fiber is more spinnable, softer, and brighter than common polyester staple fiber, and has fewer flaws and higher strength than common ones. It possesses high quality, good color fastness, better resistance to water washing, and can achieve different results by setting the color parameter. Besides, it has a small color difference and wide chromatography with yellow, green, blue, red, orange, indigo, and violet colors and the derived various chromatography.