Taught is tree bast fiber, along with a method for processing the same, the fiber being a natural textile fiber made of bark of trees except for mulberries and paper mulberries. The length of the fiber is 5 mm-65 mm. The fineness of the fiber is 0.3-2.5D. The intensity of the fiber is 0.275-0.582 N/tex. The breaking elongation rate of the fiber is 3%-7%. The method comprises the steps of peeling, sorting, degumming, skimming, drying, preserving, tanning, grinding, carding, baking, boxing and classifying, and packaging. The textile fiber is produced from a resource abundant in nature. The fiber has similar performance to bast fiber, higher intensity than cotton fiber, good dyeing properties, and wide application prospects. It can be blended with other natural fibers, man-made fibers and recycled fibers to form fiber yarn for various purposes. This method changes waste into a commodity, and brings about great economic and social benefits.