By analyzing the abundance, type and maturity of source rock organic matter, and utilizing rock pyrolysis instruments and Kinetics software, the hydrocarbon generation kinetic parameters of high-quality source rocks in the second section of the Wenchang Formation were obtained. These parameters were then integrated with typical geological heating rates as well as the burial and thermal evolution history of the depressions to clarify hydrocarbon generation characteristics and conversion rates. The results show that significant differences exist in the kinetic parameters and hydrocarbon generation characteristics of the second section of the Wenchang Formation across different sags of the Zhu Ⅲ depression. In Wenchang B sag, the activation energy distribution is relatively narrow (179.91-259.41 kJ/mol), with a lower main activation energy (213.38-217.57 kJ/mol). Hydrocarbon generation begins earlier, reaches its peak sooner, and exhibits a higher maximum generation rate. In contrast, source rocks in Wenchang C sag have a wider activation energy range (188.28-297.06 kJ/mol) and a higher main activation energy (225.94-234.30 kJ/mol), resulting in later initiation and peak of hydrocarbon generation, and a lower maximum generation rate. At present, hydrocarbon conversion rates of the Wenchang B sag source rocks are significantly higher than those of the Wenchang C sag, with rates exceeding 90% in the eastern sub-sag and 30% in the western sub-sag, while those in the Wenchang C sag generally remain below 10%. These differences in current conversion rates are mainly attributed to the combined effects of sag structural evolution and source rock hydrocarbon generation characteristics, which have significant implications for future oil and gas exploration. In particular, the eastern sub-sag of the Wenchang B sag shows substantial potential for mature oil and gas reservoir exploration , while the Wenchang C sag has relatively limited potential.