During the deep-water hydrocarbon exploration along the passive continental margin, stratigraphic records of various types of basic igneous bodies are frequently encountered. The offshore deep-water basins in Brazil provide an outstanding natural laboratory for investigating basic igneous processes. This study utilizes drilling cuttings and three-dimensional high-quality seismic data obtained during deep-water hydrocarbon exploration to conduct sedimentary basin analysis. It helps to enhance the understanding of the spatial and temporal process of basic magma in ancient sedimentary basins and provides geological basis for hydrocarbon exploration. However, few studies have been conducted to document the spatial distribution, emplacement process, and impact on sedimentary architecture of these basic igneous bodies. Therefore, this study attempts to unravel the emplacement process of basaltic magma and discuss the coupling relationship between magmatic activity and sedimentary architecture. 3D seismic data acquired from the offshore Brazil shows that a series of intrusive dykes, sills, laccoliths, and extrusive lavas are founded in the post-salt sedimentary stratigraphy. Petrographic analysis indicates that these features originate from mafic magmatism, recording the entire lifecycle of basic magma from its intrusion to eventual eruption. The intrusion pressure and compression of mafic magma induced folds, small-scale faults, and deformation of the pre-existing sedimentary strata, furthermore, subsequently altering the filling characteristics of the overlying sedimentary strata. On the basis of the law of cross-cutting relationships, it is indicated that the magmatic activity reached its peak during the Santonian and Campanian Age. The interplay between basic igneous rocks within the sedimentary basins and their host sedimentary rocks suggests a four-stage evolutionary process. Initially, the pre-thinning of salt layers and formation of salt-walled basin. This is followed by a period of continuous basin subsidence, sedimentary infill, and the growth of salt walls. Subsequently, the intrusion and extrusion of basic magma, along with localized volcanic eruptions, force folds in the sedimentary strata. Finally, the lateral migration of the subsidence center within the salt-walled basins is observed, followed by overlapping sedimentary filling and the formation of drape structures. This comprehensive study sheds light on the genesis and evolution of basic magma in sedimentary basins, outlining the spatial distribution pattern of basic igneous bodies, and their impact on sedimentary strata deformation. The insights gained possess significant implications for petroleum geological research and exploration assessments.