Abstract: The 6201 Al-alloy tubes were produced successfully through semi-solid continuous expansion forming process with an extrusion ratio 3.52. The microstructure, mechanism and change of mechanical properties were studied under T6 and TA heat-treatment processes. The results indicate that the microstructure of tubes is fully recrystallized when the demoulding temperature exceeds 520°C, and the tube strength after semi-solid continuous expansion forming process and under T6 and TA heat-treatments increases obviously with the increase of aging time, but the elongation tends to decrease obviously. The key points to the expansion forming process are to make sure that the demoulding temperature should be over 520°C, and the tensile strength of tube up to 299 MPa in T6 state with the elongation 9.4%, as well as 258 MPa with 12.4% in TA state. An evolution mechanism analysis of mechanical properties shows that the conduit tubes made from 6201 Al-alloy for bus bars with an optimum combination of tensile strength and elongation can be obtained by choosing proper continuous expansion forming process and aging treatment.