In this study, aiming at the problems of low nitrogen utilization rate caused by single nitrogen fertilizer type and "one-blast" fertilization in prosomillet production in the dry farming area of the Loess Plateau, local conventional nitrogen urea N 120 kg/hm² (TU) was taken as the control, different treatments of controlled release nitrogen fertilizer (CRNF) reduction were designed, the changes of soil nitrogen contents and prosomillet yield, nitrogen accumulation and distribution at maturity stage and nitrogen use efficiency were analyzed in order to provide support for the establishment of simple cultivation technology of prosomillet. The results show that CRNF significantly increases prosomillet yield by increasing the number and weight of spikes per unit area by 3.88% and 4.97% in two years, respectively. Prosomillet yield under CRNF reduction less than 20% is not significant different with that of TU. CRNF increases nitrogen accumulation by 1.97% to 3.21% in prosomillets at the maturity stage, and increases the distribution of prosomillet nitrogen to the seeds by 0.55%-1.18%, and prosomillet nitrogen accumulation under CRNF reduction of 20% or more is significantly lower than that of TU. CRNF improves the apparent N fertilizer utilization, N fertilizer bias productivity, N fertilizer agronomic utilization, and N physiological utilization of prosomillets, in which N fertilizer bias productivity is significantly increased by 3.88%-4.14%. Compared with TU, equal amount of CRNF significantly increases soil nitrate and ammonium N contents by 5.41%-11.80% and 4.04%-14.77% at tassel and maturity stages of prosomillets, respectively. With the decrease of CRNF, all forms of soil nitrogen show a decreasing trend in prosomillet fields, and soil nitrate and ammonium N contents under N reduction of more than 20% are significantly lower than those of TU. Correlation analysis shows that nitrogen accumulation and yield of prosomillets has a positive significant correlation (P<0.01), and nitrogen use efficiency index has the highest correlation with soil nitrate nitrogen content. In conclusion, CRNF can significantly improve soil nitrogen supply capacity in the middle and late growth stages of prosomillets, promote the uptake and utilization of nitrogen by prosomillets and thus increase its yield and economic efficiency while does not significantly reduce its yield at a moderate nitrogen reduction of 20%, so CRNF has a great potential for nitrogen reduction in prosomillets production.