Continuous extrusion is an advanced process for manufacturing copper strip. Its successfully industrial application is to manufacture copper strip. Based on finite element method (FEM), using the Deform-3D software, this paper simulates continuous extrusion forming process for copper strip, and analyzes the effect of different feedstock diameter on metal flowing temperature, effective stress, velocity, rotating torque. The results show that: feedstock diameter greatly affects the continuous extrusion forming process; Under the same rotating speed, as feedstock diameter increases, the metal flowing velocity increases. It is benefit to enhance the productivity; As feedstock diameter increases, the temperature of the billet and tooling increases, and the torque of extrusion wheel increases, which leads to tooling wear seriously.