The Iranian team defeated South Korea 3-2 (22-25, 25-21, 25-18, 22-25, 15-13) on Saturday and advanced to the final match.
China also beat Qatar 3-1 (25-22, 25-18, 23-25, 25-20) in another semis.
Iran has already defeated China 3-0 in Pool A.
The winner will secure its berth to the Tokyo 2020.