A sprinkler includes a receiving barrel, a boosting unit, a spraying unit and a protective hood. The protective hood has a side provided with a plug which has an end face provided with a mounting post. The mounting post has an inner portion provided with a mounting recess and an end portion provided with a spraying hole. The end face of the plug has a periphery provided with a plurality of filtering holes. The plug of the protective hood is inserted into the mouth of the receiving barrel when the protective hood is mounted on the mouth of the receiving barrel. The mounting post of the protective hood is mounted on the nozzle head of the spraying unit when the protective hood is mounted on the nozzle head of the spraying unit.