• High-pressure solid solution (HPSS) treatment at 5 GPa and 380 °C completely dissolves the ζ-MnZn13 phase, forming a supersaturated solid solution in Zn-0.5Mn alloy.
• The HPSS-treated alloy achieves a compressive yield strength of ~183.7 MPa, about three times higher than the as-cast counterpart, via synergistic strengthening mechanisms.
• HPSS treatment significantly improves degradation uniformity and reduces the corrosion rate, addressing localized corrosion issues in biodegradable Zn alloys.
• This work provides a novel pressure-driven strategy to enhance Mn solubility, offering a promising route for developing high-performance biodegradable Zn-based implants.