Shallow buried drip irrigation (SBDI) is an effective water-saving technology for semi-arid regions in Northeast China. However, under SBDI, the underlying mechanisms by which optimized irrigation frequency and quota regulate nitrogen metabolism enzyme activities to drive nitrogen translocation toward grains, and subsequently influence crop yield and nitrogen use efficiency, remain unclear. A two-year field experiment was conducted with three irrigation frequencies, once every 7 d (F1), 14 d (F2), and 21 d (F3), and four irrigation quotas corresponding to 60% (I1), 80% (I2), 100% (I3), and 120% (I4) of crop evapotranspiration (ETc). The results indicated that F1 increased nitrate reductase (NR) activity by 33% and 17% during the jointing and tasseling stages, respectively, compared to F3. Notably, I2 enhanced glutamine synthetase (GS) and NR activities by 19%-40% and 15%-32%, respectively, relative to other treatments. The synergistic effect of F1I2 significantly promoted nitrogen accumulation, nitrogen translocation, and contribution rate to grain nitrogen. By stimulating GS and NR activities, this treatment facilitated nitrogen translocation, leading to higher nitrogen accumulation by grain during the milky stage (GMNA), which ultimately optimized yield and partial factor productivity of nitrogen fertilizer (PFPN). In conclusion, optimizing irrigation frequency and quota under SBDI regulates maize yield and PFPN by modulating enzymatic activities to enhance nitrogen translocation to grain. These findings suggest that an irrigation frequency of once every 7 d combined with an irrigation quota of 80% ETc can maximize resource efficiency while maintaining high maize productivity in semi-arid environments.