The invention discloses a construction method for reinforcing a dredger fill embankment. A concrete cloth water insulation layer is transversely laid on the bottom of the embankment; a plurality of dredger fill reinforcement layers are laid on the upper layer of the concrete cloth water insulation layer; each of the dredger fill reinforcement layers comprises geocells and sand piles filled in thegeocells; long-strip-shaped concrete cloths are prefabricated into equilateral geocell strips with included angles of 120 degrees; the geocell strips are symmetrically distributed in pairs in the transverse direction of the embankment to form regular hexagonal honeycomb geocells; the geocells are arranged on the concrete cloths at the bottom of the embankment; the sand piles are filled in the geocells; and after the filled sand piles are rolled back and forth for dredger filling, static rolling and sprinkling for maintenance are performed. The construction method belongs to physical reinforcement. While assisting to improve the strength of the dredger filling, the construction method can improve the overall stability of the embankment by virtue of stiffener connection and effectively prevent the differential settlement and lateral deformation.