Abstract: In view of the requirements of micro-thrusters for the drag-free flight and the orbit control of pico&nano satellites, a vector control structure is designed according to the principle of α particle propulsion. We propose a hemispherical structure with α particle thrust film vector arrangement. The diaphragm driven by each ultrasonic motor provides the thrust independently, and an accurate vector control can be realized by properly adjusting the state of the substructures. The theoretical calculation and analysis show that the structure can achieve a maximum thrust force of 6.9 μN equivalent to the solar pressure on a 1 m² surface, and the resultant force is concentrated in the normal direction generally.