The invention discloses a multi-freedom-degree momentum exchange type aerospace craft posture adjusting and executing mechanism, and the mechanism is used for overcoming defects that an existing aerospace craft momentum exchange type posture adjusting and executing mechanism is redundant in structure and large in power consumption. The multi-freedom-degree momentum exchange type aerospace craft posture adjusting and executing mechanism comprises a rotor part and a stator part, the rotor part is of an integrated spherical structure and provided with a plurality of embedded magnetic-conductive magnetic poles, the magnetic-conductive magnetic poles can be permanent magnets or soft magnets, the stator part is of a spherical structure assembled by an upper hemisphere and a lower hemisphere and provided with a plurality of embedded winding magnetic poles, and the winding magnetic poles can be hollow core winding coils or winding coils containing soft magnetic cores. The rotor magnetic poles are arranged in the stator magnetic poles, homocentric with the stator magnetic poles and connected with the stator magnetic poles through ball bearings, therefore different winding power-on strategies are adopted, the rotor part can be driven to conduct spinning along different shafts, and the aerospace craft posture is adjusted through a single device based on the principle of momentum conservation.