In single-beam spin-exchange relaxation-free (SERF) atomic magnetometers, strong optical absorption induces pronounced polarization nonuniformity in the vapor cell, degrading the magnetometer performance, while the compact configuration hinders further improvement of the polarization uniformity. To address this issue, a pulsed optical pumping scheme for single-beam SERF atomic magnetometers is proposed, in which short-duration, high-power pump pulses are employed to replace continuous-wave pumping. This approach suppresses absorption-induced polarization gradients while preserving the single-beam SERF architecture. Based on a bias-field-assisted mode, we established dynamic and response signal models for the magnetometer under pulsed pumping. Analytical solutions of the models demonstrate that increasing pump power is beneficial for enhancing polarization uniformity. By considering both the magnetometer response and the photodetector shot noise, the optimal duty cycle maximizing the signal-to-noise ratio was theoretically determined to be 37%, which is close to that at 50%. Accommodating the compactness of the single-beam configuration, a miniaturized prototype based on a 1×2 fiber-optic switch was implemented, and a 50% duty cycle was adopted to enable time-division multiplexing of two magnetometers with nearly unchanged signal-to-noise ratio. Experimental results showed that under 50% duty-cycle pulsed pumping, the optimal pump power for maximum magnetometer response in a 3 mm 87Rb vapor cell increased from 0.9 mW (steady-state pumping) to 1.7 mW. With the polarization uniformity defined as the ratio of the average polarization over the cell volume to that at the beam entrance, the uniformity was improved by 46%, leading to an enhancement in magnetic field sensitivity from 14 fT/Hz1/2 to 12 fT/Hz1/2. The proposed method enables sensitivity enhancement in arrayed and integrated ultra-weak magnetic field sensors, with potential applications in high-performance magnetocardiography and magnetoencephalography.