The invention discloses a method of a multifunctional self-generating and self-cleaning water purifier and a device. The device comprises an outer casing, a cleaning handwheel, a cleaning brush and a support frame, a ceramic filter element, various water purifying filter materials, a lower blanking cover, an ejector, a water wheel generator, a discharge cock, a water purifying cock, a storage battery, an ozone generator and a switch, an illuminating lamp and a switch, a control circuit and an external socket. The water purifying function is achieved by adopting the ceramic filter element and the water purifying filter materials which can enable tap water to pass through the device; the self-cleaning function of normally and reversely pumping and cleaning is achieved by the ejector; the disassembly-free, the friction and the self-cleaning functions are achieved by the strip-shaped emery stick of the cleaning brush through mutually rotating the ceramic filter element; and the flow speed of water flow is improved by the ejector, so that the generator works to achieve the self-generating function, the illuminating function, the function of disinfecting the water purifier, the ozone water function and the power supply function, thereby solving the problems that the ceramic filter element carries out water purification and the self-cleaning is achieved without disassembly; and moreover, the invention has the advantages of simple structure and convenient operation and simultaneously can also achieve the multifunction.