The invention relates to a cleaning method for a reverse osmosis membrane device used for treatment of wastewater containing fluoride and ammonia nitrogen in the electronic industry. The reverse osmosis device comprises a first-section reverse osmosis membrane and a second-section reverse osmosis membrane connected with a concentrated water outlet of the first-section reverse osmosis membrane. The method comprises carrying out separate cleaning of the first-section reverse osmosis membrane and the second-section reverse osmosis membrane with different cleaning liquids, wherein the first-section reverse osmosis membrane unit is cleaned with a cleaning liquid capable of removing organic matters, microorganisms and colloid; and the second-section reverse osmosis membrane unit is cleaned with a cleaning liquid capable of removing the organic matters, the microorganisms, the colloid, inorganic salt crystals and various forms of silicides. Compared with a traditional cleaning method, the cleaning method provided by the invention effectively improves cleaning effect and production efficiency, shortens cleaning time, reduces the usage amount of the cleaning liquids and lowers cleaning cost; and more importantly, the method improves service life of reverse osmosis membranes and operation efficiency of a reverse osmosis system.