In order to provide a theoretical basis for high yield of maize cultivation under the mode of reduced nitrogen fertilization application，the regulative mechanism of different fertilizer application and planting density interaction effects on photosynthetic physiological characteristics，grain yield and its components of maize were studied.Photosynthetic，chlorophyll content，dry matter accumulation characteristics and yield were determined under one-year field experiment，which was carried out in Hexi arid region of Gansu province in 2019.The cultivar “Xianyu 335” was applied as research material.A split plot design was adopted with four nitrogen application amount treatments[namely 0 (N0)，150 kg/hm²(N1)，300 kg/hm²(N2)and 450 kg/hm²(N3)] as the main plot，and three plant densities[namely 60000 plant/hm²(D1)，75000 plant/hm²(D2)and 90000 plant/hm²(D3)] as the split plot.Nitrogen fertilizer application and planting density interaction effects had significant influence on photosynthetic rate，chlorophyll content，dry matter accumulation，nitrogen utilization efficiency，grain yield and its components.Under the level of same nitrogen application and different planting density，compared with the N2D1 and N2D2 treatments，the photosynthetic rate，dry matter accumulation and grain yields under the N2D3 treatments increased by 19.6% and 25.6%，54.5% and 26.1%，48.43% and 16.55%，respectively.Under the level of different nitrogen application in growth stages of maize，compared with the N0，N1 and N3 treatments，the actual ears number，kernels per ear and 1000-grain weight under the N2 treatments increased by 67.49%，37.79%，47.86% and 9.86%，2.88%，3.76% and 18.77%，10.16%，9.67%，respectively. Under the level of same planting density and different nitrogen application treatments，compared with the N1D3 and N3D3 treatments，the photosynthetic rate，dry matter accumulation and grain yields under the N2D3 treatments increased by 22.3% and 21.6%，10.81% and 9.91%，28.58% and 20.65%，respectively.Under the level of different planting density treatments，compared with the D1 and D2 treatments，the nitrogen utilization efficiency under the D3 treatment increased by 19.39% and 11.33%，respectively.The facts showed that the photosynthetic physiological characteristics，nitrogen utilization efficiency，grain yield and its components of maize could be significantly improved by applying proper amount of nitrogen fertilization under the condition of reasonable dense planting.The treatments with application interaction effect of nitrogen and planting density(i.e.，N application with 300 kg/hm² and high density of 90000 plant/hm²)could be considered as the best feasible cultivation pattern management，which could significantly improve the photosynthesis，nitrogen utilization efficiency，yield and its components，and provide technical guidance for further exploring high yield cultivation of compact planting maize in Hexi arid region.