Paleozoic buried hill is one of the high-yield fields of oil and gas enrichment in Jiyang Depression， and it is a critical reserve expansion position. Oil and gas accumulation in Paleozoic buried hills has unique petroleum geology conditions. The strata are age-old， and lithology includes carbonate rock and clastic rock. In the long geological evolution process， multi-stage structures，faults， and deep fluid activities are strong， making the buried hill have the characteristics of evolutionary superposition， structural diversity， reservoir complexity， multi-sources of oil and gas， and accumulation differences. Based on the progress of oil and gas exploration and further research of Paleozoic buried hills in Jiyang Depression since“ The 13th Five-Year Plan”， the formation and enrichment of oil and gas in Paleozoic buried hills in faulted basins were revealed from the internal geological process of hill formation，hydrocarbon generation， reservoir formation， and petroleum accumulation. The co-controlled hill formation mechanism of “compression-tension-strike-slip-denudation” was proposed. The Paleozoic buried hills had Carboniferous-Permian and Palaeogene dual-source hydrocarbon supply conditions， ternary control storage mode of “sedimentary-diagenetic environment， structurepressure coupling， and fluid-rock interaction，” oil and gas accumulation mode controlled by migration and plugging， and orderly distribution of reservoirs. Guided by these understandings， the exploration directions of Paleozoic buried hill reservoirs in Jiyang Depression was changed， and the exploration space of buried hills was expanded， laying a foundation for the evaluation of Paleozoic buried hill exploration zones， and the optimization of trap targets and breakthroughs were made in the exploration of hidden buried hills in deep slopes and negative tectonic zones. At the same time， based on the understanding degree and theoretical development status of different accumulation conditions of Paleozoic buried hills in Jiyang Depression， the next research direction of oil and gas exploration was put forward.