The invention discloses a preparation method of a fruit and vegetable fresh-keeping agent. The method comprises the following steps: firstly, taking
coptis chinensis,
pyrola rotundifolia,
rheum officinale,
polygonum cuspidatum, gallnut, chuanxiong rhizomes and
scutellaria baicalensis, and uniformly mixing the
coptis chinensis, the
pyrola rotundifolia, the
rheum officinale, the
polygonum cuspidatum, the gallnut, the chuanxiong rhizomes and the
scutellaria baicalensis which are taken; performing extraction by a
supercritical carbon dioxide fluid extraction method, and then performing separation so as to obtain an extracting solution; taking
syzygium aromaticum, cinnamon, fructus forsythiae, radix stemonae and
polygonum multiflorum, adding water to the
syzygium aromaticum, the cinnamon, the fructus forsythiae, the radix stemonae and the polygonum multiflorum which are taken, to perform decocting so as to obtain a decoction solution, filtering the decoction solution, concentrating the filtered solution under a reduced pressure, and carrying out cooling naturally, thereby obtaining the concentrated solution; and mixing the obtained extracting solution with the concentrated solution so as to obtain the fruit and vegetable fresh-keeping agent. The fruit and vegetable fresh-keeping agent prepared by the method disclosed by the invention can effectively inhibit diseases caused by
pathogenic bacteria, of picked
fruits and vegetables, can significantly reduce loss caused by the rot of picked
fruits and vegetables, and can improve the quality of picked
fruits and vegetables; in addition, the fruit and vegetable fresh-keeping agent is higher in
food safety, does not generate
pollution to the environment, and can effectively reduce the usage and the residue of synthetic bactericides and chemical pesticides.