Air refueling technology to a certain extent reflects the strength of a country’s air force,and this technology has been widely concerned. the paper summarizes the development history of hard type air tanker. Then suggests a concept of generation about hard type air tanker. The typical feature of the first generation was that the bomber being used as the refitting platform, which limited by the payload of the carrier and only provided limited external fuel supply. The typical features of second generation were refitted on the transporter, the effective external oil supplywas increased, and the fuel for the high-speed receiver at that time was added. . The third generation had a certain transportation capacity, equipped with advanced hard refueling device system, and set up a special refueling operator. The fourth generation had a certain cargo transportation capacity and developed to soft and hard three-point refueling. It had an advanced hard refueling device system. The fuel dispenser directly observed the fuel receiver and operated in a comfortable environment.The fifth generation required soft and hard refueling capability, air receiving capability, cargo and personnel transportation and medical evacuation capability, command, control and communication capability, network center capability and high survivability. The key technologies, such as general layout design technology, structure and mechanism design technology, control system design technology, were extracted to provide technical support for future equipment reform.