Based on the experimental research on prestressing steel wire(f_(ptk)=1 770 N/mm~2,d=5 mm,low relaxation of stress) at high temperature,stress and strain calculation methods of high strength steel wire considering temperature-time path was proposed.The strain calculation method,with creep,thermal expansion,stress variation and modulus variety of steel wire at high temperature being taken into account,was centred around the strain of the steel wire at high temperature.While the stress calculation method,with stress relaxation,thermal expansion,strain variation and modulus variety of steel wire at high temperature being taken into account,was centred around the stress of the steel wire at high temperature.These calculation methods were verified to be feasible by experiment and can be utilized in the analysis of fire resistance performance of prestressed structures.