Abstract: In order to explore the influence of tectonic activities on hydrocarbon accumulation conditions in Campos Basin in South America, the authors in this research investigated the dynamic background of basin formation, tectonism and sedimentation in different evolution stages, the development characteristics of source, reservoir and cover in different strata and their relationship with tectonism. And the controing effect of various structural activities on hydrocarbon accumulation conditions in Campos Basin during its evolution process was analyzed, including source rocks, reservoirs, cap rocks, traps, migration channels and oil and gas preservation. The results show that the uplift of Tristan mantle plume is the power source that causes the extension and splitting of South Atlantic Plate and the clockwise rotation of South American Plate. The Rio Grande-Walvis Ridge caused by Tristan hotspot and the scissor splitting from south to north is the main reasons for the closed-semi to closed environment of the middle South Atlantic Basin, including Campos Basin, in the stage of intracontinental rift and intercontinental rift, resulting in the formation of high-quality source rocks in rift strata, evaporite in transitional strata and marine source rocks in lower part of continental drift strata. The fault activities of Campos Basin in the rift period formed graben, semi-graben and tilting fault blocks, which controlled the distribution of subsalt source rocks, microbial carbonate reservoirs and oil and gas traps. The salt rock activities and salt diapir in the transitional layer system controlled the distribution of the salt caprock of subsalt oil and gas system, the formation of oil and gas migration channels from subsalt to upsalt and the distribution of turbidite reservoirs above salt. The revelation of these internal relations has certain reference value for the analysis of oil and gas accumulation law and controlling factors in passive continental margin and the deployment of oil and gas exploration.