Contaminated water contains various types of pollutants, the removal of which requires two or more technologies. It is imperative but challenging to develop water purifier for simultaneous removal of multiple pollutants for the sake of easy operation, low cost, and etc. Previously reported multifunctional purifiers are normally nanoparticles which require caution during use. Here, we describe a design of paper-like multifunctional purifier, which has biomass-based structure by grafting polyethylenimine derived quaternary ammonium compounds onto three-dimensional bacterial cellulose substrate. Compared to similar materials reported previously, our product exhibited strikingly higher adsorption capacities towards various metal ions including Pb2+, Cu2+, and Cr6+, anionic organic dyes including congo red, methyl orange and methyl red, and excellent disinfection efficiency towards both Gram-negative and Gram-positive bacteria. Remarkably, this purifier also demonstrated effective removal of the three contaminative species simultaneously from both simulated and local polluted water. With more virtues of superior reusability and extreme handy convenience, we hope our molecular design could inspire further efforts on the rational construction of multifunctional water purifier with easy operation. We reckon our material to have strong potential for the possible use in water treatment, especially in regions that are short of environmental infrastructures.