Moin studied at the Higher Institute of Science in Tehran and obtained his BA in literature and philosophy in 1934.

He subsequently went to Belgium and graduated in applied psychology, anthropology and cognitive science under Elmer Knowles.

On returning to Iran he carried out his doctoral research under Ebrahim Pourdavoud at the University of Tehran, culminating in a thesis with the title "Mazdayasna and its Influence on Persian Literature" for which he received a PhD with honors in Persian literature and linguistics.

Mo'in was President of the literature commission of the International Congress of Iranian Studies and Director of the Dehkhoda Dictionary Institute.

His burial chamber was vandalized in 1981 by vigilantes, thought to be due to Mo'in's ties to the political elite of the Pahlavi Era.