The fire did not prevent the flow of gas production in the major facility, but it caused gas leak and smoke emission.
All personnel have left the facility and are moving back to the city Assalouyeh.
The platform is reportedly surrounded by firefighting vessels which have managed to contain the fire.
The incident comes a few weeks after four oil tankers caught fire off the Emirati port city of Fujairah south of Persian Gulf.
The UAE described it as a sabotage attack, and the US accused Iran of being involved in the incident, but Iran categorically denied such a claim, and described the vessel incidents as “worrying and alarming”.