The present invention relates to a sediment treatment apparatus for an underground water treatment system including a drum screen. Provided is a sediment treatment apparatus for an underground water treatment system including a drum screen, wherein a collection tube in which sediment deposited inside a drum screen is collected by back washing of the drum screen is installed in parallel with the drum screen below the drum screen horizontally disposed on a bed, a first pipe is installed inside the collection tube in a longitudinal direction of the collection tube, a plurality of first nozzles adapted to spray water or air is installed inside the first pipe in a longitudinal direction of the first pipe at predetermined intervals, and the first nozzles are installed to be inclined toward an end of the collection tube so that sediment can be discharged via the end of the collection tube. As described above, the sediment treatment apparatus for an underground water treatment system including a drum screen according to the present invention has an effect in which the collection tube in which sediment is collected is installed below the drum screen, and thus the drum screen can be used for a prolonged period, thereby providing an economic advantage. Furthermore, the sediment treatment apparatus for an underground water treatment system including a drum screen according to the present invention has an effect in which sediment collected in the collection tube is caused to be discharged by forcibly spraying water or air, and thus the sediment is prevented from being rotten, thereby keeping a water intake source more hygienic and safe.(AA) Discharge of sedimentCOPYRIGHT KIPO 2016