The Ligue 1 side are keen to strengthen their attack after an underwhelming 2016-17 campaign in which they had to settle for fourth place in the table.
They already secured the services of Memphis Depay from Manchester United during the January window and are now looking to bring in Traore.
Lyon president Jean-Michael Aulas has confirmed they are in advanced talks and reports suggest they have already agreed a five-year deal with the 21-year-old.
"We absolutely want to complete this deal," Aulas told reporters.
"Traore is keen to come to Lyon.
"Negotiations are in the advanced stages and we do not intend to let anything come between this transfer."
Traore joined Chelsea in January 2014 and spent 18 months on loan at Vitesse before returning to Stamford Bridge ahead of the 2015-16 campaign.
He failed to secure regular first-team action at the Premier League giants, though, and was farmed out on loan to Ajax last term, where he played a key role in their run to the Europa League final, scoring twice against Lyon in the semi-finals of the competition.