Al-Zn-Mg-Cu alloy was 3GPa pressure treated, and the effect of high pressure treatment on nanoindentation creep property of Al-Zn-Mg-Cu alloy was investigated by using nanoindentation. The results show that indentation creep in Al-Zn-Mg-Cu alloy before and after 3GPa pressure treatment can occur at room temperature, 3GPa pressure treatment can reduce creep deformation of Al-Zn-Mg-Cu alloy at room temperature at different pressure and time, and leads to the creep resistance of Al-Zn-Mg-Cu alloy rises.