The aluminum tube with rectangle section can be produced by two-pass drawing process including non-plug and with-plug drawing. It is an effective method to study the deforming mechanisms by simulation, based on which the section varying of two-pass drawing got schemed and the relevant dies with reasonable dimensions got designed. The dynamics model and elasto-plastic FE model of the non-plug and with-plug drawing were established based on FEM software, then the simulation was performed. The sizing section of drawing die got optimized with angle β=178°, which eliminated instability. The influence of different semi-die angle 2 a on drawing load was researched, and a proper value of 2 a and 1 a was found. The touch boundary and touch-stress distribution of transitional drawing were achieved. Furthermore the residual stress and spring-back strain distribution after final drawing were achieved, which contributes to modifying the dimensions of rectangle sizing section.