In this paper, a feasibility analysis of a modular uniform magnetic field coil is provided. The modular uniform magnetic field coil consists of n2 square coil units. By adjusting the number of coil units or the current in the coil units, different sizes and patterns of uniform magnetic field coils can be easily formed to meet different experimental requirements. An analytical model of the modular uniform magnetic field coil considering the gap between coil units is first developed based on the Biot-Savart law and the superposition principle, and the analytical model is verified by the 3D finite element method. Then, the characteristics of the modular uniform magnetic field coil are analyzed and compared with the traditional Helmholtz coil, demonstrating the advantages of the proposed magnetic field coil. These advantages precisely verify the original intention of the modular uniform magnetic field coil proposed in this paper. Finally, a robustness analysis of the modular magnetic field coil is performed, including the effects of gap between coil units and assembly misalignment on the performance of the modular uniform magnetic field coil.