The invention discloses a closestool brush and relates to a brush. The closestool brush is characterized in that brush hairs (11) are uniformly distributed on the outer edge of a diameter-expanding round brush head (13); one end of a brush rod (10) is connected with the inner end of the diameter-expanding round brush head (13), and the other end of the brush rod (10) is hinged with one end of a rotary rod (4) by a rivet (7); the middle part of the rotary rod (4) penetrates in a sleeve (15); a horizontal handle (5) is arranged on the side surface of one end of the sleeve (15), and the two ends of a spring (3) arranged at the other end of the rotary rod (4) in a sleeving manner prop against the end surface of one end of the sleeve (15) and the end surface of one end of a bending connection rod (2) respectively; and the other end of the bending connection rod (2) is provided with a vertical handle (1). According to the closestool brush disclosed by the invention, by utilization of hinging between the brush rod and the rotary rod, dirt on the upper wall of an elbow of a sewer pipeline of a closestool can be cleaned by controlling the brush hairs of the diameter-expanding round brush head though the vertical handle.