Abstract: In order to study the generation mechanism and deformation law of warping(cross bowing,lengthwise bowing and twisting) in thin steel strips during temper rolling,strip warping models with tension on-line and without tension off-line were established using ANSYS software.The mechanical mechanism of warping deformation under the two states and the influence mechanism and law of factors were analyzed.According to the analysis results,it is indicated that the warping deformation is caused by the uneven distribution of plastic deformation(mainly vertical extension) along the thickness direction during temper rolling,not the uneven distribution in width.Under the guidance of simulation data,serious cross bowing after temper rolling in a continuous annealing process line was investigated,and a good result was gotten after improving the rolling process.