The utility model discloses a thread bundling mechanism which is suitable for being mounted on a baling machine for trimming and bundling objects needing to be baled. The thread bundling mechanism comprises a thread bundling frame, thread bundling components and a thread trimming component, wherein the thread trimming component is mounted in the middle of the thread bundling frame; and the thread bundling components are mounted on the thread bundling frame on the two sides of the thread trimming component respectively and comprise a motor, a driving chain, a plurality of gears, a thread bundling shaft and a thread bundling head, wherein the motor is mounted above the thread bundling frame, the gears are pivotally connected onto the thread bundling frame, the thread bundling head extends out to form an arc-shaped hook body and is fixed at one end of the thread bundling shaft, the other end of the thread bundling shaft is sheathed and fixed with the gears, and the driving chain is wound on an output shaft of the motor and all the gears. The thread bundling mechanism provided by the utility model can automatically bundle the objects needing to be baled with threads, thereby reducing the manual operation and improving the working efficiency.