Preparation method of lily phloem juice sample

The invention provides a preparation method of a lily phloem juice sample, which comprises the following steps: cutting off a lily leaf from a stem, and immersing the cut part of the lily leaf into a chelating agent solution; after the lily leaves are taken out, the lily leaves are wrapped with wet tissue, and notches are exposed; vertically hanging the lily leaf, and completely soaking the cut part in ultrapure water; placing the lily leaves in a dark environment, and collecting juice exuded from the lily leaves; and centrifugally separating to obtain supernate, and filtering to obtain a juice sample. The lily leaves are vertically hung, so that phloem juice can be rapidly and directly extracted and collected, and the problems that the amount of juice exuded from phloem is small, the exuding speed is low, and extraction and collection are time-consuming and labor-consuming are solved. And the preparation method is simple to operate, less in intermediate pollution and relatively high in purity of the extracte