Abstract: Integrating sphere cooling, with its unique advantage of being an all-optical cooling method that eliminates the need for gradient magnetic fields required in magneto-optical traps, demonstrates broad application prospects in compact cold-atom systems, particularly in space atomic clocks. The integrating sphere plays a crucial role in stabilizing or optically pumping trapped atoms. Conventional integrating sphere laser cooling devices typically employ spherical integrating spheres, where the uniform radial distance in all spatial directions results in limited tunability of light intensity parameters at the sphere's center. Moreover, the miniaturization of integrating spheres leads to non-uniform light field distribution inside the sphere, reducing atomic cooling efficiency. From a geometric perspective, a spherical integrating sphere is essentially a special case of an ellipsoidal integrating sphere with specific parameter adjustments. Therefore, ellipsoidal integrating spheres offer more degrees of freedom and broader application potential. To further reduce the volume of the integrating sphere while improving light field uniformity and enhancing atomic cooling efficiency, this study breaks through the geometric limitations of traditional spherical integrating spheres and innovatively proposes and validates a light field control theory based on ellipsoidal structures. Through analytical derivation and numerical experiments, we demonstrate that when incident light is parallel to the Z-axis, an ellipsoidal integrating sphere can simultaneously achieve enhanced light field convergence and improved uniformity, addressing the core challenges of insufficient light intensity and uncontrolled distribution in miniaturized systems. This achievement provides a transformative design paradigm for next-generation compact cold-atom devices.