Abstract: The effects of Cu on the microstructure and mechanical properties of ZL114A alloy were studied by transmission electron microscope(TEM), scanning electron microscope(SEM) and room temperature tensile test. The results show that Cu inhibits the formation of GP zones, β'' and β'' phases. However, under the conditions of appropriate aging system and reasonable Cu content, there is θ'' phase in ZL114A alloy, realizing β'' and θ'' double precipitated phase strengthening.When the aging system is 180℃/8 h and 0.54 wt% Cu is added, the tensile strength of ZL114A alloy increases from 350 MPa to 384 MPa, the yield strength increases from 310 MPa to 338 MPa, and the elongation decreases from 2.5% to 2.2%. After adding Cu, the fluidity of ZL114A alloy decreases. When using Cu to improve the strength of ZL114A alloy, the Cu content should not be too high.