To investigate the response patterns of photosynthetic characteristics, chlorophyll fluorescence parameters, and yield of super hybrid rice leaves to nitrogen (N) application rate and planting density, this study used the hybrid indica rice Yixiangyou 2115 as experimental material and adopted a split-plot design with planting density as the main plot factor and N application rate as the subplot factor. Four levels of planting density were set: 125 300 hills/hm², 166 700 hills/hm², 200 800 hills/hm², and 250 600 hills/hm². Similarly, four levels of nitrogen application rate were established: 0 kg/hm², 75 kg/hm², 150 kg/hm², and 225 kg/hm². The results showed that in terms of photosynthetic characteristics, with the increase in nitrogen application rate, the net photosynthetic rate (Pn) and stomatal conductance (Gs) of rice both exhibited a gradually rising trend, while the intercellular CO₂ concentration (Ci) showed an opposite trend. As the planting density increased, Pn, Gs, and transpiration rate (Tr) all demonstrated a trend of first increasing and then decreasing. Regarding chlorophyll fluorescence characteristics, with the increase in nitrogen application rate, the maximum photosynthetic quantum yield of PSⅡ (Fv/Fm), photochemical quenching coefficient (qP), non-photochemical quenching coefficient (qN), and quantum yield of regulated energy dissipation [Y(NPQ)] all showed a trend of first rising and then falling, while the actual photosynthetic quantum yield of PSⅡ [Y(II)], apparent electron transport rate (ETR), and quantum yield of non-regulated energy dissipation [Y(NO)] exhibited the opposite trend. As the planting density increased, Fv/Fm, Y(Ⅱ), ETR, qP, and qN all showed a trend of first increasing and then decreasing. In terms of yield, with the increase in nitrogen application rate, rice yield showed a trend of first increasing and then decreasing, with a turning point at 150 kg/hm² of nitrogen application rate. Similarly, as the planting density increased, rice yield also showed a trend of first increasing and then decreasing. Under the experimental conditions, the suitable nitrogen application rate for Yixiangyou 2115 was 150 kg/hm² and the suitable planting density was 200 800 hills/hm², at which the rice yield could reach 9 267.55 kg/hm². Further calculations using regression equations revealed that the optimal nitrogen application rate was 155.00 kg/hm² and the optimal planting density was 191 300 hills/hm², under which the highest yield of 9 384.64 kg/hm² could be achieved. In conclusion, moderate nitrogen application and medium planting density can enhance the light adaptation ability of super hybrid indica rice leaves, improve their photosynthetic rate and efficiency, and help optimize yield components, thereby achieving high rice yield.