The invention provides a preparation method for a galvanized steel strand of a cable. The method comprises the steps that six galvanized steel wires are obtained, and every two galvanized steel wires are intertwisted in a spiral manner to form one preliminary twisted wire; three preliminary twisted wires are intertwisted with a rubber tube to form a pre-stress galvanized steel strand, and the rubber tube is positioned among the three preliminary twisted wires; the rubber tube is composed of a tube body and gel filled into the tube body, through holes are formed in the tube body uniformly, the gel includes a mixture of resin, aluminum and ceramic powder in the mass ratio of 8:2.2:1.6. The pre-stress galvanized steel strand has waterproof, anti-corrosion and saline-alkaline corrosion resistant functions, the service life of the strand is long, the tensile strength is high, less steel is used, the cost is low, and the using effect is good.