Affected by the Caledonian-Hercynian Orogeny tectonic movements, the Yingshan Formation in Block N of M Oilfield has undergone intense denudation, which has brought considerable challenges to isochronous stratigraphic correlation. The distribution patterns of carbonate lithological associations have not been clearly understood, which severely hinders the accurate prediction of reservoirs and the efficient development of oil reservoirs. Taking the Yingshan Formation in the northern Block N of the high-denudation zone in M Oilfield as the research target, a high-resolution astronomical chronostratigraphic scale has been conducted and a high-precision sequence stratigraphic framework has been established through the application of Milankovitch cycle analysis, based on integrated data including cores, thin sections, well logging, and seismic data. Rock types have been classified, vertical lithological association sequences have been established, and the distribution patterns of lithological associations within the high-precision isochronous stratigraphic framework, as well as their differential impacts on karstification, have been revealed. The research findings are as follows: the ultra-long eccentricity cycle (2.4 Ma), the ultra-long obliquity cycle (1.2 Ma), and the long eccentricity cycle (405 ka) of the Milankovitch cycles correspond to the fourth-order, fifth-order, and sixth-order sequences, respectively. Based on this correspondence, the Yingshan Formation has been divided into two third-order sequences, four fourth-order sequences, eight fifth-order sequences, and 23 sixth-order sequences. The lower part of the Yingshan Formation is characterized by being thicker in the east and thinner in the west, while the upper part is thicker in the south and thinner in the north. Eight types of carbonate rocks have been identified within this formation, which have been categorized into eight lithological association types (A-type to H-type)) according to their vertical stacking patterns. The lower section of the Yingshan Formation features the E-type to H-type assemblages, while the upper section has the A-type to D-type assemblages. Significant regional variations in the distribution of lithological associations have been found within the high-precision sequence stratigraphic framework. In the second member of the Yingshan Formation, the associations gradually transition from A-type, C-type, and E-type to B-type, F-type, and G-type from south to north. In the third member, the associations shift from from B-type and C-type to F-type and G-type from southwest to northeast. In the fourth member, the associations change gradually from B-type to C-type from west to east. It was confirmed that B-type association is most favorable for the development of high-quality karst reservoirs, with C-type, E-type, and F-type following in effectiveness.