The recently discovered Yangchang phosphate mine in Zhenxiong County, Zhaotong City, Yunnan Province is an ultra-large-scaled buried phosphorus ore. Previous research on this ore mainly focused on the aspects of ore deposits, while the sedimentary geochemistry and the paleoenvironmental study as well as the coupled inorganic (δ13Ccarb) and organic (δ13Corg) carbon isotopes and their relationships in the early Cambrian were rarely reported. In this study, three drill cores (ZK001, ZK0701, ZK1512) in this phosphorus ore were selected for high-resolution investigations of δ13Ccarb and δ13Corg, indicating that: ① both δ13Ccarb and δ13Corg show negative shifts in the uppermost Precambrian Dengying Formation and its overlying basal Zhujiaqing Formation, which is consistent with the global Basal Cambrian Carbon Isotopic Excursion (BACE), likely attributed to the oxygenation of organic carbon reservoir. ② However, we did not find significant positive shifts in the immediately overlying strata (i.e., Zhujiaqing Carbon Isotopic Excursion, ZHUCE), which may be caused by sedimentary hiatus given that the Yangchang phosphate ore is mostly intra-clastic phosphorus-rich deposits. But compared with the composite profile of δ13Ccarb in South China, we propose that this phosphorous ore mainly formed during the Fortunian stage. ③ Comparisons for the paired δ13Ccarb and δ13Corg values in the drill core ZK001 and ZK0701, we find that the average value of the ΔCcarb-org (difference between δ13Ccarb and δ13Corg) is 28.8‰ and 22.2‰ in Dengying Formation, 31.7‰ and 31.7‰ at the bottom of the Zhujiajing Formation, and 29.6‰ and 29.8‰ in the middle and upper of the Zhujiaqing Formation, respectively. In addition, the averaged ΔCcarb-org values continued to decrease to 27.6‰ from the top of the Niutitang Formation to the Mingxinsi Formation in the ZK0701 drill core. Notably, the decoupled δ13Ccarb and δ13Corg occurring in the middle of the Zhujiaqing Formation may be caused by the increased primary productivity or buried organic carbon. In summary, the high-resolution paired inorganic and organic carbon isotopes in this wok enhance our understanding of the formation time of phosphorus ore at Yangchang, shed light on associated paleoenvironmental changes, and benefit the regional stratigraphic correlation.