Abstract: In order to evaluate the effects of different regulation measures on the soil agrochemical properties, labile organic carbon content and humus composition of oil tea plantations in Ninghua County, five regulation measures were designed, including the application of biochar-based organic fertilizer alone (T1), planting Chamaecrista rotundifolia alone (T2), planting Indigofera amblyantha Craib alone (T3), biochar-based organic fertilizer combined with planting Chamaecrista rotundifolia (T4), and biochar-based organic fertilizer combined with planting Indigofera amblyantha Craib (T5), with a control treatment (CK) receiving no regulation measures. The results showed that: (1) Compared with the control group (CK), the fertilization, grass planting, and combined fertilization-grass regulation treatments (T1−T5) all significantly (P＜0.05) increased the soil pH value, organic matter content, and total and available nutrient contents. Specifically, the soil pH value increased by 0.11−0.39 units, the content of organic matter increased by 7.96%−69.79%, the contents of total nitrogen, total phosphorus and total potassium increased by 159.09%−327.27%, 15.71%−104.29% and 67.77%−103.62% respectively, and the contents of alkaline hydrolysis nitrogen, available phosphorus and available potassium increased by 126.00%−299.08%, 17.23%−120.95% and 58.63%−135.10% respectively. (2) The application of biochar-based organic fertilizer, grass planting, and combined fertilization-grass regulation all had positive effects on soil labile organic carbon in oil tea plantations. (3) The application of biochar-based organic fertilizer, grass planting, and combined fertilization-grass regulation measures could effectively improve the content and components of soil humus, thereby improving the content and quality of soil organic matter. Comprehensively considering the cost of planting and fertilizer, the optimized soil regulation measures for the Camellia oleifera plantation in Ninghua County was biochar-based organic fertilizer with planting Chamaecrista rotundifolia, i.e., applying 3 kg of biochar-based organic fertilizer per Camellia oleifera tree (trench application with a wide and depth of 30 cm), while simultaneously planting Chamaecrista rotundifolia (row sowing with a plant and row spacing of 30 cm).