[en] In this study, we investigated the influence of the pump beam on the electronic and nuclear spin polarization homogeneity in the nuclear magnetic resonance gyroscope (NMRG). An analysis method was proposed based on the three dimensional simulation of the spin polarization spatial distribution. The pump power loss due to the aperture on the structure was considered. The average spin polarization and inertia measurement sensitivity were measured experimentally to demonstrate the simulation results. The results indicate that the nuclear spin polarization retains good homogeneity at different beam diameters, while the homogeneity of the electronic spin polarization highly depends on the beam diameter. It also can be seen that the electronic spin polarization homogeneity is more sensitive to pump power than pump beam diameter, while the nuclear spin polarization homogeneity is more sensitive to pump beam diameter than pump power. Moreover, the optimized beam diameter is obtained to balance the polarization and its homogeneity. The study provides reference for the design of the pump beam diameter and beam shaping structure in NMRG. (paper)