A novel near-space aerostat based on quasizero wind-layer field for station-keeping was investigated. The working principle and system composition of the aerostat were introduced first. After that, a model comprising of dynamics, altitude control and energy circle was established. The properties of station-keeping and energy circle of the aerostat were studied in two typical working modes: flight speed limitation and north-south displacement limitation. With the weather input of Changsha, it is found that, compared with uncontrolled free-flying mode, the aerostat can achieve long resident in a 100 km diameter range under both working modes. Moreover, the energy consumption of the aerostat with flight speed limitation mode is lower than that of the other mode.