Abstract: To improve the FEM computational efficiency and implement its online application, an 1.5-dimension rigid-plastic FEM (RPFEM) model was developed as the fast solution to the strip rolling process, where the shape function and the B and Hessian matrixes of 1.5-dimension RPFEM were derived to decrease the number of unknown values and degrees of freedom. The different strip rolling processes were solved successfully by the software RF-1.5D we developed, and the rolling force, iteration steps and computing time were investigated with the data acquired from a certain plant. The calculated value of rolling force is basically in agreement with the measured value, i.e., an error less than 10%. The iteration steps in the solution for a single pass rolling are thus less than 35 and take 100 ms only, which means that the computing time for every iteration step is shortened by 1.5-dimension RPFEM in comparison with that by 2D. The precision and high efficiency of the 1.5-dimension RPFEM are therefore proved available to meet the basic requirements for online prediction.