To address the problem of insufficient magnetic field uniformity in solenoid coils for rubidium optical clocks under limited size constraints, this paper conducts a parametric modeling study on a multi-segment C-field coil structure inside a magnetic shield cylinder using the COMSOL Multiphysics simulation software. The number of coil segments, turns density, and other structural parameters are optimized to enhance the magnetic field uniformity in the target region along the central axis. The research results show that after optimization, the magnetic field non-uniformity in the [80, 120] mm region of the five-segment coil is reduced to 0.078%, while that of the seven-segment coil is further reduced to 0.033%. This research provides important technical insights for achieving a high-uniformity C-field in rubidium optical clocks within confined spaces.