Abstract: Memristors, as emerging electronic components, have attracted extensive attention due to their potential to integrate storage and computation. Two-dimensional organic thin films (2D OTFs) possess atomic-level precise layered structures, tunable electronic properties, and excellent mechanical flexibility. These materials enable efficient electrical conductivity control through precise microstructural and surface chemical regulation. In recent years, memristors based on 2D OTFs have become a research hotspot, driven by their ultrathin geometry, superior flexibility, and tunable electrical performance. This review examines memristors based on 2D OTFs highlighting their preparation methods, resistance switching mechanisms, and application prospects. Four major preparation methods are discussed: solvothermal synthesis, interfacial polymerization, single-phase synthesis at room temperature, and electrochemical polymerization. Solvothermal synthesis forms crystalline 2D OTFs through high-temperature reactions in organic solvents. Interfacial polymerization enables controlled synthesis of 2D OTFs with adjustable thickness and dimensions. Single-phase synthesis of 2D OTFs at room temperature addresses challenges of precise thickness control and harsh conditions. Electrochemical polymerization produces uniform, porous films with tunable thickness and superior electrical properties. Resistance switching mechanisms in 2D OTFs memristors include ion migration, charge transfer, redox reactions, conformational changes, and multiple mechanisms. Ion migration involves redox reactions under an electric field, enabling reversible electron transfer and conductivity changes. Charge transfer relies on charge redistribution in donor-acceptor systems, facilitating electron transport and resistance switching. Redox-active units in 2D OTFs enable reversible redox processes, crucial for non-volatile memory. Conformational changes in polymer chains create efficient charge transport pathways, enhancing device performance. The multiple mechanisms utilize light-induced electron movement to generate changes in current or voltage, achieving controllable variations in resistance. The review also addresses challenges and future directions, such as improving material solubility, enhancing mechanical stability, and addressing stability issues in high-temperature and high-humidity environments.