The yield strength of the steel component gradually decreases under high temperature. As a result, the structural performance of the steel component on the bridges will be greatly affected by the on-deck fire disaster. Taking the steel pylon of a three-pylon suspension bridge as an example, this paper mainly studied the influence of the fire disaster on the structural performance of the steel pylon and the entire bridge. First of all, the temperature distribution inside the fire and steel pylon was obtained by the numerical simulation of different on-deck fire scenarios near the middle steel pylon. Secondly, the change of the structural static performance of the bridge under different fire scenarios was obtained by a nonlinear analysis. The results showed that under the effect of a serious vehicle fire, larger than 80 m2 area of the middle steel pylon was under the temperature up to 800 ℃, and the maximum temperature would exceed 1 000 ℃, which can greatly affect the structural performance of the steel pylon. Obvious changes of stress and formation of the middle steel pylon were discorverd, which means 4.6 mm vertical residual deformation, 53.8 mm lateral residual deformation and 70 MPa stress reduction. However, the stress and deformation of the main cable and girder only showed minor changes.