To improve storage of peach fruit, the effect of slightly acidic electrolyzed water (SAEW) dissolved without and with Ca(NO₃)₂ (at concentrations of 0.5, 1, and 2%) on fruit browning, antioxidant system, tissue Ca²⁺ content and distribution, metabolism of cell wall polysaccharides, and related modifying enzymes was evaluated at 25°C for 8 d. Results showed that Ca(NO₃)₂ and SAEW had synergistic effects on reducing ethylene production, respiration rates, and browning index; inhibiting the accumulation of free radicals and lipid peroxidation, and polyphenol oxidase activity; maintaining fruit firmness and higher levels of phenolic compounds, enzymatic and non-enzymatic antioxidants; increasing tissue Ca²⁺ content and distribution; and delaying the disassembly of cell wall polysaccharides and activities of cell wall-modifying enzymes. These results revealed that 1% Ca(NO₃)₂ in SAEW treatment has potential as a commercial cleaning process to extend fruit life, through suppressing browning and solubilization of pectin, protecting the antioxidant system, and facilitating Ca²⁺ absorption.