A6061-T6 aluminum alloy and DP590 duplex steel with a galvanized layer for resistance spot welding, the investigation of welding current on the A6061-T6 aluminum alloy / DP590 steel joint interface intermetallic compound and the effect of shear resistance. The results found that when the welding current increased, the intermetallic compound layer first became thicker and thinner, while the joint shear force always increased, and when the welding current reached 13 kA, the shear force was 4.0 kN.