The invention discloses a roller brush for protecting a curb. The roller brush comprises a supporting rod, an upper blocking plate, a front blocking plate, side blocking plates and a brush head, wherein the supporting rod is obliquely arranged; the lower half parts of the upper blocking plate and the supporting rod are fixedly connected; the front-end edges of the front blocking plate and the upper blocking plate are fixedly connected, and the front blocking plate keeps a drooping state; the brush head is fixedly connected with the tail end of the supporting rod, and the upper blocking plate and the front blocking plate are used for shielding the brush head; and a steel rod is connected at the front section of the tail end of the supporting rod, and the side blocking plates are fixedly arranged at the two ends of the steel rod. The roller brush disclosed by the invention has the advantages that the blocking plate devices are added on the roller brush, so that the pollution for the curb when manual brushing construction of roads can be effectively avoided; the front blocking plate can play a role in partitioning between the curb and the roller brush head, the distance between the side block plates and the brush head can be adjusted by telescopic movement, and the curb is protected from the side surfaces in brushing; and after the roller brush added with the blocking plates is used for brushing construction, the phenomenon that the curb is polluted by the brushing material can be avoided, the appearance of the curb can not be damaged, and the application effect is good.