The present invention discloses an optical fiber twig tree, which comprises a plurality of plastic optical fiber bundles and a stand structure; wherein the plastic optical fiber bundles are designed in a shape corresponding to the branches of the optical fiber twig tree and tied into a fixed position by a tie. The plastic optical fiber bundles are disposed at the bottom of the stand, and coupled with an illuminating structure. A hook at one end of a main branch of the stand is latched into a screw of a branch base, such that the whole stand with the plastic optical fiber bundles can swing up and down freely to adjust their position at an angle. Further, the main stand comprises a plurality of branch bases to constitute the optical fiber twig tree, and such product can be used as a decoration for festivals or Christmas.