The application discloses a cabinet system of a data center, including: a cabinet body, including a plurality of rack modules between a front side thereof and a rear side thereof; a plurality of data server hosts, detachably installed on the corresponding rack modules; and a power supply module, disposed on the corresponding rack module in the cabinet body, and coupled to at least one of the data server hosts. The power supply module includes a standardized frame compliant with a first specification. The standardized frame includes an accommodating groove for plug-in assembly of a power core unit having different parameters (e.g., output powers or dimension specifications). Thus, the power core unit having different parameters can be assembled through the standardized frame, providing the cabinet system with flexible configuration of power supplies as well as convenient maintenance or replacement.