Ultra high temperature drilling is the key technology of high temperature geothermal power generation, the breakthrough of which will enhance the development of the deep high-temperature geothermal power generation industry. We analyze the major technical problems of high temperature geothermal drilling, which include high-temperature well control, ultra high temperature drilling mud, high-temperature well cementing and completion, tools and instruments that suit for the high temperature condition, high temperature well trajectory measurements and control, rock-breaking efficiency in high temperature condition, and so on. As for those problems, the experts both at home and aboard have developed many technological responses, such as, the safety well control of the high temperature geothermal drilling, anti-high-temperature cement, anti-high-temperature down-hole tools, well trajectory monitor and control, anti-high-temperature drill bits and drilling rate, and so on. We also provide an example of the deep high-temperature geothermal drilling in Kenya at last.