In order to find the impact on longitudinal resistance of continuously welded rails on bridge under different longitudinal resistance of the lines, based on the principle of the interaction between bridge and track, an integrative rail-bridge-pier calculation model of CWR on bridge is developed. Take simple-supported and continuous beam bridge as example to analyze the influence of continuously welded rails on bridge under different line resistance. The result shows that whether simple-supported or continuous beam bridge, the additional expansion forces which conducted by the constant resistance are smaller than the bilinear and power-exponential resistance, and the gap becomes greater as the increasing of the expansion length, and the calculation of the bilinear and power-exponential resistance becomes more and more similar. Besides, the calculation of the braking forces which conducted by the constant resistance is smaller than the bilinear and power-exponential resistance, while the displacement between the rail and beams is bigger, and has exceeded the calculation standard; the breaking joint of rail conducted under different longitudinal resistance is basically the same, but decreased gradually with the maximum line resistance increased.