The cutter’s lateral displacement along the paper’s movement is the main reason which causes the folding accuracy problem. The folding stem is deformed in actual working condition, which causes the cutter emerge lateral displacement. The structure of folding stem is complex, it needs the combination of mechanics and finite element analysis to get the fitting formula relation of the folder’s deformation and the loadings. By the dynamic coefficients, which express the relation of loadings between the working velocity and clearances, the cutter’s lateral displacement model is established based on studying the relation of the cutter’s lateral displacement and the folder stem’s deformation. By the model, the folding accuracy is studied in different working velocities and conditions.