Abstract: This paper introduces the millimeter wave drilling technique abroad,which uses the high-power gyrotron transmitter to emit intensive beam of millimeter-wave electromagnetic energy for melting or vaporizing rocks,and uses high pressure air or nitrogen for carrying cuttings(micron-sized powder actually),including the principle of drilling,theoretical research status and achievements and conclusion obtained by laboratory experiment.It can shorten the drilling time by eliminating the process of changing bit and running casing and cementing as conventional drilling method.The laboratory experiment shows that ROP of millimeter wave drilling is related to the millimeter wave power,specific energy for rock vaporization and absorption power density.Millimeter wave drilling technology will be a novel idea and method for improving drilling rate and reducing cost.