A physical address determining method, apparatus, and device, and a storage medium, and belongs to the field of solar power generation, includes: controlling at least two slave nodes to sequentially start up, and detecting a change status of an input voltage of the master node; dividing a photovoltaic power generation system into a plurality of photovoltaic strings; and for each candidate photovoltaic string, controlling any slave node located in the candidate photovoltaic string to start up and other slave nodes to shut down, and using the physical address as a physical address of the candidate photovoltaic string. This disclosure provides a manner of automatically determining a physical address of a photovoltaic string, thereby implementing photovoltaic-string locating and expanding a system function range. When an anomaly occurs, the anomaly can be eliminated in a timely manner, thereby improving system stability.