The near-space long duration lighterthanair has great applications, so the high altitude airship and superpressure balloon have been attracting worldwide interest. The long duration flight of superpressure balloon in the near-space had been successfully achieved abroad. To accomplish the long duration flight of airship in the near-space, the core technologies in the fields of environment perdition, airship envelope material, power supply, propulsion, etc, need breakthrough advancements. This study analyzes the environment elements of the near-space, and researches the influence of the atmospheric density, atmospheric temperature, wind field, ozone, and radiation on the airship. Moreover, the altitude, trajectory and pressure control technologies of the superpressure balloon are investigated, and the feasible technologies for the high altitude airship long duration flight are proposed, which is useful for high altitude airship design, manufacture and flight.