A passive optical network (PON) method and device using network sharing are disclosed. The PON slicing method includes identifying network elements included in a plurality of physical PONs (pPONs), abstracting the identified network elements to be recognized as a same software block, generating a plurality of virtual PONs (vPONs) according to a user requirement using the plurality of pPONs, and mapping the generated plurality of vPONs by performing PON slicing on the abstracted network elements.