Construction method of subsection prefabricated underground diaphragm wall

The invention relates to the technical field of underground engineering, in particular to a construction method of a subsection prefabricated underground diaphragm wall, which comprises the following steps: constructing a guide wall of the underground diaphragm wall, excavating soil in a groove of the underground diaphragm wall in a framing manner, backfilling mucky soil into the groove after the groove is formed, transporting the lower section prefabricated underground diaphragm wall to a groove opening, sinking to a designed elevation, and locking. The method comprises the steps that firstly, the upper-section prefabricated underground diaphragm wall is hoisted to the position above the lower-section prefabricated underground diaphragm wall, a connecting joint of the upper-section prefabricated underground diaphragm wall and the lower-section prefabricated underground diaphragm wall is constructed, finally, locking of the lower-section prefabricated underground diaphragm wall is relieved, a whole formed by