A consortium of key extracellular enzymes plays a critical role in the biological fermentation of organic material during aerobic composting. The succession of physicochemical properties and the associated functional extracellular enzymes were evaluated during the aerobic composting process. Different starting C/N ratios were achieved by adding pine needles to decipher which and how the extracellular enzymes improve composting efficiency. Overall, the compost with C/N ratios of 25 harbored significantly higher temperatures, germination indices, the degradation of organic matter, and higher extracellular enzyme activities such as cellulase and dehydrogenase, indicating enhanced composting maturity. The combined activities of protease and β-glucosidase, dehydrogenase and cellulase, and β-glucosidase and cellulase indicated a significant effect on composting efficiency during the mesophilic, thermophilic, and mature stages, respectively, suggesting a significant contribution to the development of composting efficiency. The pot experiment further indicated that the aerobic composting end product of pile 2 had a significant plant-growth-promoting effect compared to piles 1 and 3. When taken together, this study highlights that the appropriate C/N ratio of 25 to 35 induced significantly higher efficiency aerobic composting, and the influence was attributed to the selection and stimulation of functional extracellular enzymes.