The invention discloses an EP composite ultra-short curl-free fiber post-treatment production method and device. The production method comprises the steps of pre-spinning protofilament bundling, dipping bath, primary tow stretching, secondary tow stretching, tow curling, tow laying, tow loosening and shaping, tow cutting, packaging and the like. The corresponding post-treatment device comprises abundling frame, a dipping bath tank, a water bath tank, a steam drafting box, an oiling machine, a yarn stacking machine, a curling machine, a drying setting machine, a cutting machine and a packagingmachine which are sequentially arranged on a workbench from left to right. According to the EP composite ultra-short curl-free fiber post-treatment production method and device, through specific post-treatment methods such as dipping bath, drafting, curling, shaping and cutting, the melting point of the skin layer of the prepared EP composite ultra-short curl-free fiber can be reduced, the bonding strength of non-woven fabric is improved, the doping proportion of the fiber is reduced, and the downstream production cost is reduced.