A passive optical network (PON) system supporting wireless communication includes an optical line terminal (OLT) configured on a central office, an optical distribution network (ODN), and a plurality of optical network units (ONUs) respectively configured on user ends. The ODN is connected to the OLT and the ONUs in a one-to-many manner. The OLT sends a downstream optical signal to the ODN, and receives an upstream optical signal. The ODN circularly guides the optical signal to each ONU. Each ONU receives and reflects the downstream optical signal, processes the received downstream optical signal, receives and processes the upstream optical signal, carries an electrical signal to be uploaded into the upstream optical signal, and carries data received by a remote antenna into the upstream optical signal. Through the above architecture, the PON system supports wireless communication.