Turner who picked up the Magners League coach of the season award last year, leaves the Dragons after six years in charge and wished the club well.
"I've enjoyed my 6 years at the Dragons and am immensely proud to have been involved with developing this Region. I wish all the players and staff my best wishes for the remainder of the season," he said.
In the Heineken Cup this year the Dragons finished the Pool stage with no wins to their name and currently find themselves in ninth place in the Celtic League table.
Edwards will combine the Dragons role with his duties as head coach of Wales Under 20's.