Iran started developing drones, or unmanned aerial vehicles (UAVs), in the 1980s during its eight-year war with Iraq.
The US and Israel accuse Iran of dispatching fleets of drones to its proxies in the Middle East, including Lebanon's Hezbollah movement, the regime of Syria's President Bashar al-Assad and Yemen's Huthi rebels.
Video aired on state television showed Iran's armed forces chief of staff General Mohammad Bagheri and army commander Abdolrahim Mousavi visiting the underground site.
"More than 100 combat, reconnaissance and attack drones belonging to the army are kept for operations in this base located in the heart of the Zagros mountains," the report said.
Bagheri, quoted by the official news agency IRNA, described the site as a "safe operational base for strategic drones".
"We never underestimate threats, we never assume the enemy is asleep, and we are constantly alert and vigilant," he added.
Mousavi told state television the base was located "several hundred metres (yards) underground", without giving further details.
State TV said the flagship of the fleet was the "Kaman-22", a drone equipped with missiles and able to fly at least 2,000 kilometres (1,245 miles).