Abstract: To address the challenges of recalcitrant lignocellulose degradation,prolonged composting duration,and substantial nutrient loss during the natural composting of Castanea henryi involucres,this study utilized involucres collected from Zhenghe County,Nanping City,Fujian Province,as raw material.An L₉(3⁴)orthogonal experimental design was employed to systematically investigate the effects of four additives—EM microbial inoculant,RW decomposition accelerator,extracellular enzymes from Auricularia auricula and extracellular enzymes from Lentinula edodes—on the composting process and product quality.Key parameters including pile temperature,pH,electrical conductivity(EC),germination index(GI),total carbon,total nitrogen,total phosphorus and total potassium were monitored and comprehensive evaluation was conducted in accordance with the NY/T 525—2021 Organic Fertilizer standard.The results indicated that the overall influence of the four additives on the composting efficacy of C.henryi involucres followed the order:EM inoculant > RW accelerator > L.edodes extracellular enzymes > A.auricula extracellular enzymes.Among them,EM inoculant and RW accelerator were identified as the core factors promoting composting.The optimal additive combination was determined to be 6‰ EM inoculant + 6‰ RW accelerator + 20 mL A.auricula extracellular enzymes + 20 mL L.edodes extracellular enzymes.This formulation significantly accelerated the onset of the thermophilic phase,prolonged its duration,enhanced the decomposition and mineralization of organic carbon,and effectively reduced losses of nitrogen,phosphorus,and potassium,thereby simultaneously improving composting efficiency and final product quality.These findings provide a scientific basis and technical reference for the environmentally sound treatment and high-value resource utilization of forestry by-products such as Castanea henryi involucres.