The distribution of light and nitrogen within a plant's canopy is critical for photosynthesis and overall crop performance. However, it remains unclear whether maize can adjust its canopy structure to optimize both light and nitrogen distribution when intercropped with soybeans. To investigate this, a three-year field experiment (2022-2024) was conducted in the Loess Plateau using a split-plot design that included three planting patterns: sole maize (SM), sole soybean (SS), and intercropping of maize (IM) and soybean (IS), along with two nitrogen levels: no nitrogen application (N0) and nitrogen application (N1). The distribution of light and nitrogen, as well as the transformation of the source-sink relationship of maize under different planting patterns were investigated. The results indicate that, compared to SM, intercropped maize (IM) adjusted its canopy structure (leaf angle and leaf area) to capture more photosynthetically active radiation (PAR), increased nitrogen uptake, reduced both the nitrogen extinction coefficient (KN) and the light extinction coefficient (KL), and improved the coordination of nitrogen and light distribution within the canopy. Consequently, the maize maximized solar radiation utilization, promoting the accumulation of photoassimilates (source) and mitigating premature leaf senescence caused by nutrient transfer to kernels (sink) after the silking (R1) stage. Ultimately, this process resulted in increased maize yield. This study examined the optimization mechanisms of source-sink relationships in intercropped maize through the lens of canopy light-nitrogen synergy, thereby providing a theoretical foundation for stable-yield cultivation in the Loess Plateau.