Construction method of underground diaphragm wall

The invention relates to the technical field of building construction, and discloses a construction method of an underground diaphragm wall, which comprises the following steps: S1, construction preparation: leveling a site, measuring and positioning, and determining a guide wall earth cutting position according to the axis of the underground diaphragm wall; s2, manufacturing a guide wall; the underground diaphragm wall needs to be slotted during construction, since the underground diaphragm wall adjacent to a subway structure is sensitive to deformation of a foundation, soil above a sand layer needs to be reinforced by stirring piles before construction of the underground diaphragm wall so as to control deformation of side walls during grooving, and guide walls need to be arranged along two sides of the underground diaphragm wall before grooving construction so as to prevent surface soil from collapsing. And the grooving precision is ensured. Slurry is conveyed through a 7PLN type slurry pump, recycled throu