According to the rolled technology and characteristics of roller, the thermo-mechanical coupled mathematical model was established for roller elastic deformation. The law of roll casting force distribution was calculated and the influence of process parameter on the force and roller elastic deformation was analyzed, thus the key boundary conditions were determined to calculate roller elastic deformation and its experimental verification was performed. The results show that casting force distributes asymmetrically and decreases after it increases to 100 MPa. Casting roller elastic deformation distributes the similar saddle-shaped curves under different casting process parameters and the maximum is 0.303 mm. The calculation results agree with the measured data very well.