In order to provide a theoretical basis for the evaluation of the thermal response of prestressed concrete structures under fire conditions and their fire resistance design in practical engineering, the effects of fire temperature, temperature holding time and protective layer thickness on the internal temperature field of prestressed concrete T beams are discussed by carrying out temperature holding tests and finite element simulation studies under the action of high temperature of fire. Based on the experiments, the heating curves of different beam sections are obtained, and 21 sets of nonlinear transient temperature field models of prestressed concrete T-beams under different conditions are established by using the finite element software ABAQUS, and the influence law of fire time, fire temperature and concrete protective layer thickness on the temperature field distribution is systematically analyzed. The results show that the maximum temperature of the T beam at 1,2 and 3h is 780,790 and 793 °C , respectively, under the constant temperature of 800 °C . In the case of constant 3h , when the ambient temperature is 600,700 and 800 °C , the maximum temperature of the T beam is 592,693 and 794 °C , respectively. In addition, increasing the thickness of the concrete protective layer can effectively slow down the transfer of fire temperature to the internal structure, and significantly reduce the temperature of steel bars and prestressed bars, thereby reducing material damage. The results can provide theoretical basis and technical reference for the evaluation of the thermal response of prestressed concrete structures under fire conditions and their fire resistance design in actual engineering.