Jaidee, of Thailand, rolled in a 5-foot putt to defeat Gonzalo Fernandez-Castano and Sung-Hoon Kang.
The three had finished regulation play at Jeju Island's Pinx Golf Club in 4-under-par 284.
Kang had a 68, Fernandez-Castano 69 and Jaidee and 70 to get into the playoff.
Jaidee also won the Indonesian Open last month.
"I enjoyed winning a tournament for the second time this year," he said.
Seve Benson (69), Rafael Cabrera-Bello (70), Ernie Els (71) and third-round leader Robert-Jan Derksen (76) shared fourth place at 2-under 286.