The Iranian boxer defeated Uzbekistan’s Fanat Kakhramonov in Men's 75kg weight class on Monday.
Mousavi will book his place at the Olympics if he defeats his Mongolian opponent Byamba Erdene Otgonbaatar.
The event was initially due to take place in the Chinese city of Wuhan, but was relocated to Amman, Jordan due to the coronavirus outbreak.
Thirty-five countries and 221 boxers are competing at the event, with 41 men's and 22 women's berths up for grabs at the Olympics.
Iran has sent eight boxers to the event.