Disclosed is a magnetic-fluid momentum sphere, which is used for satellite attitude adjustment. The magnetic-fluid momentum sphere comprises stators and a spherical shell. The stators are classified into three groups, axes of the three groups of stators are orthogonal to each other, each group comprises two stators arranged symmetrically about the center of the spherical shell, and the inner surfaces of the stators are spherical surfaces. The spherical shell is formed by combining two hemispherical shells, the material of the spherical shell is a non-ferromagnetic material, the inner surfaces of the stators closely adhere to the outer surface of the spherical shell, there is no relative movement between the spherical shell and the inner surfaces of the stators, and the spherical shell is filled with magnetic fluid. The magnetic-fluid momentum sphere achieves a small size and mass, low costs, and small coupling among the axes.