Thallium is a highly toxic metal, and trace amount of thallium(I) (Tl⁺) in potable water could cause a severe water crisis, which arouses the exploitation of highly-effective technology for purification of Tl⁺ contaminated water. This report proposes the multi-layered Prussian blue (PB)-decorated composite membranes (PB_x@PDA/PEI-FP) based on the aminated filter papers for Tl⁺ uptake. Extensively characterization by Fourier transform infrared spectrometer-attenuated total reflectance, scanning electron microscope, thermogravimetric analysis, X-ray photoelectron spectroscopy and X-ray diffraction were performed to confirm the in situ growth of cubic PB crystals on filter paper membrane surfaces via the aminated layers, and the successful fabrication of multi-layered PB overcoats via the increasing of aminated layers. The effect of PB layers on Tl⁺ removal by PB_x@PDA/PEI-FP from simulated drinking water was evaluated as well as the influence of different experimental conditions. A trade-off between PB decoration layer number and PB distribution sizes is existed in Tl⁺ uptake by PB_x@PDA/PEI-FP. The double-layered PB₂@PDA/PEI-FP membrane showed the maximum sorption capacity, but its Tl⁺ uptake performance was weakened by the acid, coexisting ions (K⁺ and Na⁺) and powerful operation pressure, during filtrating a large volume of low-concentrated Tl⁺-containing water. However, the negative effect of coexisting ions on the Tl⁺ uptake could be effectively eliminated in weak alkaline water, and the Tl⁺ removal was increased up to 100% without any pressure driving for PB₂@PDA/PEI-FP membrane. Most importantly, PB₂@PDA/PEI-FP displayed the high-efficiency and high-selectivity in purifying the Tl⁺-spiked Pearl River water, in which the residual Tl⁺ in filtrate was less than 2 μg·L^–1 to meet the drinking water standard of United States Environmental Protection Agency. This work provides a feasible avenue to safeguard the drinking water in remote and underdeveloped area via the energy-free operation.