The invention discloses an initial storage structure for a seawater desalting system. The initial storage structure comprises a sealed barrel body with a water inlet pipe and a water outlet pipe, wherein two spiral zinc plating copper wires in vertical distribution are arranged in the sealed barrel body; the axial line of the spiral zinc plating copper wires is horizontal; one end of each spiral zinc plating copper wire passes through the barrel wall to extend to the outer side of the sealed barrel body; two motors are arranged at the outer side of the sealed barrel body; the output ends of the two motors are respectively connected with one ends, extending to the outer part of the sealed barrel body, of the two spiral zinc plating copper wires; a pipe opening of the water inlet pipe is positioned between the two spiral zinc plating copper wires in vertical distribution; a square opening with the area being 1 square meter is arranged on the top surface of the sealed barrel body; the inner wall of the sealed barrel body is provided with a climbing ladder; the climbing ladder is positioned under the square opening. The initial storage structure is used for solving the problem that in the prior art, strip-shaped sundries in the sea water can easily block a water pump filter screen.; the goals of reducing the suction probability of the strip-shaped sundries by a water pump and reducing the filter screen cleaning frequency through pump dismounting by workers are achieved.