Abstract: The accurate identification and subdivision of high-precision sequences play a fundamental role in establishing an essential framework for analyzing the spatio-temporal evolution of depositional systems in continental rift basins within rift-climax period and for interpreting shifts in paleoclimates. This study proposes a sequence stratigraphic framework focusing on the study of the second Member of the Liushagang Formation (the L2 Member) in the Weizhou Exploration Area of the Beibu Gulf Basin. Using three-dimensional seismic data with well-log data, integrating seismic stratigraphy, well-log stratigraphy and cyclostratigraphic approaches, the low frequency sequence is extended to high frequency sequence to realize the identification and subdivision of high-precision sequences of lacustrine rift basin within rift-climax period, and calibrated against an astronomical timescale. The results facilitated the subdivision of the L2 Member into three third-order sequences (SQ1 to SQ3, bottom-top). Furthermore, astronomical cycle analysis revealed that the total deposition duration of the L2 Member was 12.15 Ma: 3.24 Ma for SQ1, 6.48 Ma for SQ2, and 2.43 Ma for SQ3. According to astronomical cycle characteristics, combined with wavelet transform analysis, 8 fourth-order and 33 fifth-order sequences within SQ1. Additionally, 16 fourth-order and 66 fifth-order sequences were recognized within SQ2, and 6 fourth-order and 23 fifth-order sequences were identified within SQ3. The average duration of these sequences was approximately 0.405 Mafor fourth-order and 0.1 Ma for fifth-order sequences. The long orbital period signals show different confidence and signal strength in MTM spectrum analysis and evolution spectrum analysis respectively. Tectonic activity is assumed to be the predominant influence on the development of low-frequency sequences in rift basins. The SQ1 highstand systems tract was characterized by the development of sublacustrine fans, which approximately formed during the Early Eocene Climatic Optimum (EECO). It is hypothesized that the evolution of this set of sublacustrine fans was influenced by this climatic event. The results of study provide theoretical basis for depicting characterization of deep-water sedimentary fills in lacustrine rift basins witihin rift-climax period, offering valuable guidance for hydrocarbon exploration and resource assessment in the region.