Soil carbon and nitrogen nutrients play a crucial role in plant growth. To investigate the effects of carbon and nitrogen on crop growth，a field experiment was conducted in the yellow soil region of central Guizhou. Four treatments were established，including control(CK)，glucose(G)，urea(U)，and glucose + urea(GU). The impacts of exogenous carbon and nitrogen on crop growth，soil microbial community，and metabolism were assessed. The GU treatment significantly increased the fresh weight，dry weight，and stem diameter of rapeseed compared to other treatments(P<0.05)，and the plant height of rapeseed was also the highest in the GU treatment. The soil pH content of the G，U and GU treatments was lower than that of the CK treatment，while the soil total nitrogen，alkali-hydrolyzable nitrogen，and organic matter content were higher than those of the CK treatment. The predominant species of soil microbial community in the GU treatment was Arthrobacter，suggesting its potential importance in the GU treatment. At KEGG Pathway levels 2，nitrogen metabolism and carbohydrate metabolism were prominent. Among the nitrogen cycle metabolism pathways，the nitrogen fixation metabolism pathway dominated in the G treatment，while the nitrification metabolism pathway dominated in the U treatment. In the carbon cycle metabolism pathway，there were 18 significantly different metabolic pathways between the GU treatment and the other three treatments，with 6，11 and 3 pathways in CK，G and U，respectively. In the GU treatment，18 significantly different metabolic pathways were identified，with the metabolic genes mainly originating from Arthrobacter. These genes included glucose kinase glk(K00845)，ribose-5-phosphate isomerase B rpiB(K01808)，1，6-diphosphofructokinase glpX(K02446)，6-phospho-3-hexulose isomerase hxlB(K08094)，and phosphofructokinase pfk and pfp(K21071). Structural equation modeling demonstrated a direct and significant impact of carbon cycle metabolic genes on rapeseed growth and yield(P<0.001). This study laid the groundwork for investigating the influence of carbon and nitrogen on crop growth from a microbial perspective and provided theoretical support for research on crop yield improvement.