The invention discloses a comprehensive control method of rice diseases, insect pests and weeds. By organically combining rice planting and duck raising in a paddy field, the weeds and the insect pests in the paddy field are eaten by ducks, soil is massaged and loosened by the ducks, tillering of rice plants is stimulated, effects of muddying water and fertilizing the field are generated, effectsof killing the insect pests and the weeds are good, through a seed pretreatment step, seeds are subjected to sterilization and disinfection, bacterial breeding is effectively prevented, healthy growing of rice is facilitated, a disease control effect is good, meanwhile, the seeds are soaked in sodium selenite, thus a selenium content of the rice seeds is increased, by applying a selenium-enrichedslow-release organic fertilizer into the paddy field, a trace element content of the soil can be effectively increased, nutrient value of the soil and the rice is improved, and a rice yield per mu israised; and in the control method, selenium-enriched slow-release organic fertilizer granules are produced by means of fertilizer granulation equipment, and the selenium-enriched slow-release organicfertilizer produced by the fertilizer granulation equipment is in a shape of small granules, and thus is evenly applied during fertilization, so that growing of the rice is facilitated.