In view of the realistic demand of the national strategy for resource and energy drilling equipment, in regard to the different process characteristics of large-depth geological drilling and hydrocarbon & geothermal drilling, keeping in mind the two objectives of “multi-process compatibility and wellhead automatic adaptation”, and with inheriting and integration of the advantages of the existing systems, this paper proposes a dual-power AC variable frequency top drive drilling system design applicable to diamond core drilling and hydrocarbon & geothermal drilling. Through detailed comparison with other typical top drive systems in terms of the overall structure, control system and key components for the automation of wellhead operations, the design can give full play to the advantages of multi-processes, high efficiency and automation, and achieve a good balance between the advanced technology, process adaptation and industrial economy.