With a method for constructing a water intake pipe, a vertical shaft 10 is constructed, and a shield tunnel 12 is constructed by causing a shield driving machine to advance from the vertical shaft 10 toward a seashore by breaking the wall of the vertical shaft 10. The tunnel 12 becomes a water intake pipe after the tunnel is constructed, and is built by annularly assembling segments 14 one after another at the rear side of the shield driving machine in line with the advancement thereof. Two types of segments 14, RC segments 18 and ductile segments 20, are used. The segments 20 are provided with water intake pores clogged by clogging members. After the tunnel 12 is constructed, workmen enter the shield tunnel 12 with compressed air supplied thereinto, and remove the clogging members of the ductile segments 20. After the clogging members are removed, sea water is gradually taken into the tunnel 12 through the water intake pores 20c while lowering the compressed air pressure so that sea water does not rush into the tunnel 12.