Clarifying the seepage barriers within the reservoir that hinder fluid seepage is a crucial fundamental task for developing(adjusting) plans in oilfields. To investigate the hierarchy and types of seepage barriers in the delta front sand reservoir of the Zhujiang Formation in Oilfield A of the Pearl River Mouth Basin, continuous coring sections of drilling, closely-spaced well logging analysis and well correlation were conducted. Based on established sedimentary microfacies and sedimentary evolution of the study area, adhering to the reservoir architecture theory, a hierarchical analysis method combined with comprehensive production dynamic analysis was employed to elucidate the causes, hierarchy, and types of seepage barriers. Furthermore, the relationship model between the hierarchy of seepage barriers and reservoir structure was developed. The research results play a significant role in guiding the precise tapping of oil reservoirs potential and improving the development effect.