The present invention relates to a wheel brush, which is composed of a base plate, springs, chucks, iron sleeves and bristles. When a bristle unit is to be mounted, the iron sleeve of the bristle unit is placed on the upper side of the base plate, two anti-rotating lugs are made to correspond to two lug slots in the base plate, and the chuck is inserted from the lower side of the base plate; after a gasket is fixed in a counter bore in the lower side of the base plate, a wing nut is continuously pressed upwards, so that the spring is tensioned, and two guiding lugs of a fixing pin come into contact with the bottom ends of guiding slots in the iron sleeve; and after the wing nut is rotated by 90 degrees, the bristle unit can be locked.