Abstract: The effects of friction on metallic rheology and mechanical parameters during plane strain compression were studied. Based on the 2-D and 3-D thermo-mechanical coupled finite element theory, the mechanical parameters, lateral spread and deformed metal flow pattern were calculated in different friction conditions by using MSC/Superform finite element software. The metallic deformation law was analyzed with pure aluminium at room temperature on a self-developed large specimen plane strain thermomechanical simulator under different friction conditions at top and bottom interfaces. The results show that the deformation load enhances and the lateral spread lessens with increasing friction coefficient. The difference in friction coefficient at top and bottom interfaces results in U-type deformed specimens, and the inhomogeneity of deformation is more severe when the difference between top and bottom friction coefficients increases.