Tight sandstone reservoirs, characterized by low porosity, low permeability, strong heterogeneity, and difficulty in "sweet spot" prediction, represent a critical focus and challenge in current unconventional oil and gas exploration and development research. As one of the most important filling minerals in tight sandstone reservoirs, chlorite profoundly influences reservoir properties and hydrocarbon-bearing potential. Clarifying the enrichment characteristics of chlorite and its regulatory mechanisms on reservoir properties and hydrocarbon occurrence capacity will provide crucial insights for the precise prediction of hydrocarbon-bearing "sweet spots" in tight sandstones. We systematically analyzes the mechanisms and controlling factors of chlorite’s impact on the hydrocarbon-bearing potential of tight sandstone reservoirs, focusing on its occurrence modes, genetic mechanisms, and coupling relationships with diagenetic evolution. Research indicates that chlorite primarily exists in reservoirs in three forms: grain-coating, pore-lining, and pore-filling. Among these, grain-coating chlorite forms through the combined effects of precursor clay mineral transformation, detrital material replacement, and pore fluid precipitation. Pore-lining chlorite originates from the transformation of sedimentary clay coatings, dissolution and recrystallization of Fe-Mg-rich materials, or mixed transformation and direct crystallization processes. Pore-filling chlorite precipitates from Fe-Mg-rich pore waters or forms via the transformation of smectite and illite. Chlorite formed during different diagenetic stages exerts dual effects on reservoirs: positive effects include enhancing rock compressive strength, inhibiting pressure dissolution, promoting dissolution processes, and suppressing quartz overgrowth; negative effects involve pore-throat blockage and permeability reduction. Chlorite formation spans the entire sedimentary-diagenetic evolution process, and its influence on reservoir hydrocarbon potential exhibits spatiotemporal variability and multi-factor synergy. Core controlling factors include chlorite occurrence, thickness, continuity, and interactions with diagenetic stages. Hydrocarbons primarily occur as films adsorbed onto chlorite surfaces and within its intercrystalline pores, or as isolated/aggregated particles. Minerals with larger specific surface areas exhibit higher adsorption potential energy for hydrocarbons. Chlorite from different diagenetic stages possesses varying adsorption capacities, with pore-lining chlorite’s intercrystalline pores demonstrating the strongest hydrocarbon adsorption capability. "Sweet spot" reservoirs typically feature chlorite with moderate thickness and complete continuity, often distributed in high-energy sedimentary environments and avoiding zones of thick cementation. Moderate development of pore-lining chlorite provides favorable space for hydrocarbon charging and storage. We provide a comprehensive mineralogical and petrological basis for the "sweet spot" prediction of tight sandstone hydrocarbon reservoirs, which is of great significance for deepening the understanding of hydrocarbon enrichment mechanisms in tight reservoirs and optimizing exploration and development strategies.