In order to help the scientific exploration of ultra-deep formation and oil and gas discovery over 10000m in China， two sets of automatic drilling rig for 12000m extra?-deep wells were developed which is equipped with 15m ultra-high drilling floor base， 4600kW winch with high load ratio， 3000hp five-cylinder drilling pump set， 9000kN AC frequency conversion top drive device， etc.， to meet the needs of drilling operations for myriametric wells with ultra-high pressure complex condition. Ultra-large capacity pipe string automatic processing equipment and integrated control system are accompanied to meet the requirements of automatic storage and discharge of myriametric drilling tool， the full automated process of pipe string from the yard to the wellhead was achieved. Electric drive equipments were comprehensively applied with more accurate control， more environment friendly operation， low temperature environment adaptability and higher safety. Equipements such as top drive device， generator set and domestic inverter are locally made rather than imported. The field application showed that the two sets of automatic drilling rig for 12000m extra?-deep wells has an integrated drilling speed of up to 1.6m/h， and the tripping speed is 24.8columns/h. Through the remote online detection and expert diagnosis system， the average failure rate is reduced by 50% compared with the in-service drilling rig， and the drilling operator can be reduced by 3 people/shift， as a result， the labor intensity of drilling personnel can be greatly reduced. It provides equipment support for China’s oil and gas field development in myriametric formations.