<p>Photovoltaic (PV) walls are prone to overheating during summer, which adversely affects their thermal and electrical performance. Current solutions primarily involved ventilation and phase change energy storage, which often proved ineffective when applied independently. This study developed a PV wall integrated with multi-channel ventilation and composite phase change materials (PV-MV-CPCM), and investigated its operational performance and strategies during summer. Experimental results indicated that increasing the ventilation wind speed by 2.0 m/s enhanced the combined thermal-electrical efficiency by 10.8%. Nonetheless, during outdoor temperature rise period, increasing the number of activated airflow layers and inlet wind speeds led to additional heat transfer to the internal surface, resulting in the wall’s internal surface temperature to rise by 0.8 °C. To address this, a segmented-time ventilation control strategy was proposed based on the temperature differences across various layers. Compared to full-time ventilation, the segmented-time ventilation effectively mitigated the impact of high outdoor temperatures, reducing the wall’s internal surface peak temperature by 1.1 °C, increasing the peak heat removal efficiency by 2.1% and improving the combined thermal-electrical efficiency by 3.8%. This study provided effective strategies for mitigating the overheating of PV walls during summer, thereby enhancing both thermal and electrical performance.</p>