<p>The effects of Er and Zr on the microstructure and mechanical properties of Al-30Zn-2Cu high-zinc aluminum alloy were investigated, along with the evaluation of the hot tearing susceptibility of the high-zinc aluminum alloy through constrained rod casting (CRC) experiments and stress rod casting experiments. The results indicate that: (1) The tensile strength, yield strength, and elongation of the Al-30Zn-2Cu-0.1Er-0.1Zr alloy reached 418 MPa, 347 MPa, and 4.8%, respectively. The tensile strength and yield strength were improved by 9% and 23% compared to the Al-30Zn-2Cu alloy, respectively. The addition of Er and Zr enhanced the mechanical properties of the high-zinc aluminum alloy. (2) In the CRC experiments, the high-zinc aluminum alloy exhibited a low level of hot tearing sensitivity values. In the stress rod casting experiments, the high-zinc aluminum alloy showed a smoothly rising stress–load curve. Hot tearing tests demonstrated that high-zinc aluminum alloys have low hot tearing susceptibility. The study found that with the addition of Er and Zr, the <i>α</i> + <i>η</i> microstructure in the alloy transitioned from a large-sized continuous distribution to a small-sized dispersed distribution. Furthermore, the addition of Er and Zr reduced the size of the nanoscale <i>η</i> phase within the α-Al grains and increased the number density of the η phase. This research provides innovative insights for the alloy design of high-zinc aluminum alloys.</p> Graphical abstract <p></p>