The invention discloses a diaphragm wall and a construction method thereof, wherein the construction method is carried out according to the following steps: step 1, the underground obstacles at the trench section position and the two sides of the trench section of the diaphragm wall are cleared; step 2, two ranges of
cement stirring piles are respectively and symmetrically distributed at the two inner sides of the trench section of the diaphragm wall to reinforce; step 3, an integral pouring type concrete guide wall is formed at the top parts of the
cement stirring piles, the cross section of the guide wall is L-shaped, one end of the guide wall is arranged at the inner sides of the
cement stirring piles, and the other end of the guide wall crosses the top parts of the cement stirring piles; after the guide wall is built, an integral pouring type concrete rigid terrace is formed at the other end of the guide wall; step 4, the trench construction is carried out between the two ranges of cement stirring piles through a trench
machine, and the
bentonite mud is adopted in the trench section to protect the wall during the trenching; step 5, after the trenching is completed and reaches the
scale height, slags of the trench bottom are removed, a diaphragm wall reinforcement cage is hoisted to be placed in the trench section, and a guide
pipe method is adopted to carry out
underwater concrete pouring; and step 6, after the concrete reaches the design strength,
high pressure grouting is carried out on the bottom of the diaphragm wall. The diaphragm wall can integrate soil blocking, water resisting and bearing into a whole through the method, so good social and
economic benefits are obtained.