The effect of Cu on the peak aging precipitates, tensile properties and intergranular corrosion properties of 6000 series aluminum alloy were investigated by OM, TEM, HRTEM, tensile and intergranular corrosion test. The results shown that the addition of Cu promoted the precipitation of the peak aging phase of the alloy. With the Cu content increasing from 0 to 0.18wt.% and 0.37wt.%, the precipitates size of the peak aging alloy decreased significantly, and the volume fraction increases from 4.05% to 4.61% and 5.36%. The strength of the corresponding alloys increased from 421MPa to 448 MPa and 459MPa. According to HRTEM, the main precipitates of the three alloys in peak aging state was β "phase, and L phase was also found in the alloy with 0.37 wt.% Cu added. The addition of 0.18 wt.% Cu improved the intergranular corrosion resistance of the alloy, while the addition of 0.37 wt.% Cu decreased the intergranular corrosion resistance of the alloy. It was found that the addition of 0.18 wt.% Cu promoted the precipitation of β "phase in the alloy, and the width of the precipitation free zone (PFZ) at the grain boundary was refined to 51.92nm. The addition of 0.37 wt.% Cu promoted the precipitation of the strengthened phase and changed the type of the precipitated phase. In addition, it was found that the addition of 0.37 wt.% Cu significantly roughened the width of the PFZ at the grain boundary, and the PFZ width was 60.20nm. Combined with aging precipitates, tensile strength and intergranular corrosion, it is found that 0.18wt.%Cu alloy has excellent comprehensive properties.