The invention provides a retard-bonded prestressed tendon and a preparation method thereof. The retard-bonded prestressed tendon comprises retarded binders, a prestressed steel strand and a protectivejacket; the retarded binders comprise 100-120 parts of epoxy resin, and the protective jacket comprises the following raw materials by weigh: 100-150 parts of base polyethylene and 10-20 parts of polythene grafted with unsaturated anhydride. According to the retard-bonded prestressed tendon, the polythene grafted with the unsaturated anhydride is introduced into the raw materials of the protective jacket, and the protective jacket and the retarded binders are anchored stably and firmly through unsaturated anhydride cured epoxy resin; the interaction between the retarded binders and the protective jacket is improved, not only is the mechanical property good, but also the gradual loss of the mechanical property is low; the retard-bonded prestressed tendon can maintain high integrity for a long time under the cyclic repeated fatigue load in practical application. The retard-bonded prestressed tendon provided by the invention has long durability, and the preparation method of the retard-bonded prestressed tendon is simple; and large equipment and a complicated process are not required, and the retard-bonded prestressed tendon is economically and socially significant.