In atomic clocks, the uniformity of the static magnetic field generated by the C-field coil directly influences the measurement accuracy of atomic energy level transition frequencies and the stability of the clock. To address the issue of insufficient field uniformity in finite-length solenoids under spatial constraints, this paper conducts a parametric modeling and optimization study on a multi-segment C-field coil structure placed inside a magnetic shielding tube, based on the COMSOL Multiphysics simulation software. The results demonstrate that by adopting a multi-segment coil structure and optimizing winding parameters such as the number of segments and turns density, the magnetic field uniformity within the target region along the central axis can be significantly improved. Specifically, under optimal parameters, a five-segment coil reduces the magnetic field non-uniformity to 0.078% over a 40 mm range, while a seven-segment coil further optimizes the magnetic field non-uniformity to 0.033% over the same range. In this research, a compact multi-segment coil structure is optimally designed for the high-uniformity C-field of rubidium atomic optical clock in a limited space, and an efficient parameter determination method is provided.