Prestressed wire for bridge and production process of prestressed wire

The invention relates to a prestressed wire for a bridge. The wire comprises the following chemical components in percentage by weight: 0.45%-0.65% of C, 1.5%-2.3% of Si, 0.4%-2.2% of Mn, 0.3%-0.7% of Ni, 0.1%-0.8% of Cr, 0.07%-0.35% of Nb, 0.02%-0.6% of Ti, 0.05%-0.1% of V, 0.01%-0.05% of Mo, less than 0.015% of P, less than 0.015% of S, 0.02%-0.06% of composite rare earth, and the balance of iron and inevitable other trace impurities. A production process of the prestressed wire disclosed by the invention comprises the following processes of pickling, phosphorization, saponifying, cold rolling, cold drawing and galvanizing. The prestressed wire disclosed by the invention is applied to the bridge construction, so that a lot of bridge construction materials can be saved; the construction time is shortened; and the engineering quality stability is ensured. The prestressed wire has relatively high corrosion resistance and relatively good fatigue resistance, so that the service life of a cable is greatly prolonged; and the economic benefits and social benefits are significant.