A PON architecture, a method for realizing data transmission with the PON architecture and an optical network device are provided. The PON architecture includes an optical line terminal (OLT) supporting multiple channels, and one or more optical network units (ONUs) supporting one or more channels under a same optical distribution network (ODN). The OLT/ONU is configured to acquire the number of channels and/or corresponding channels supported for transmitting data and transmittable states of the supported channels, distribute the data to be transmitted to one or more supported channels for transmitting, the data is preferentially transmitted on a channel with an earliest transmittable start time point, and transmission end time points of channels for transmitting the data are similar or data transmissions end at a transmittable end time point. The ONU/OLT is configured to receive data on channels supported by ONU/OLT itself and reassemble the data accordingly based on transmission rules.