River blocking and intercepting structure in river channel and construction method of river blocking and intercepting structure

The invention relates to a river blocking and intercepting structure in a river channel and a construction method of the river blocking and intercepting structure. The method comprises the following steps that two rows of first Larsen steel sheet piles which are oppositely arranged are driven at set positions in the river channel; a first enclosing purlin is arranged on the outer side of each row of first Larsen steel sheet piles; a plurality of first supporting pieces are arranged between the two first enclosing purlins; the river water between the two rows of first Larsen steel sheet piles is pumped and drained; two rows of second Larsen steel sheet piles which are oppositely arranged on one side, corresponding to the two rows of first Larsen steel sheet piles, in the river channel are driven; a second enclosing purlin is arranged on the outer side of each row of second Larsen steel sheet piles; a plurality of second supporting pieces are arranged between the two second enclosing purlins; and the river wate