A fresh-cut vegetable fresh-keeping packaging bag is made of a PE/PP (polyethylene/polypropylene) or OPP (oriented polypropylene) film. Multiple unidirectional bubbles protruding outwards are distributed on one side of the packaging bag, the PE/PP or OPP film is 0.5mm in thickness, and the unidirectional bubbles are 0.01mm in thickness, 2-6mm in diameter and 3-6mm in spacing. A fresh-cut vegetable fresh-keeping process adopting the packaging bag includes: 1, selecting the fresh-keeping bag, putting treated fresh-cut vegetables in the fresh-keeping bag to 4/5 of the volume, and then sealing the bag; 2, when placing the packaged fresh-cut vegetable packaging bag in a breathable fresh-keeping transfer box, enabling the side with the bubbles to be perpendicular to the ground so as to prevent the bubbles from being crushed; 3, placing the fresh-keeping transfer box at cold chain temperature (3-5 DEG C) for storage and transportation. By the packaging bag, the packaged fresh-cut vegetables can have good breathable and moisture permeable effect and are also convenient to apply since the unidirectional bubbles have good permeability of gases such O2 and CO2 and water permeability, excessive moisture condensation can exist in the unidirectional bubbles in priority, water drops are avoided, and the fresh-cut vegetables are less prone to breeding pathogenic bacteria and going bad.