The utility model relates to a pulley assembly for roller skates, which comprises a pedestal, a swinging arm and a pulley, wherein, the upper end of the swinging arm is hinged on a pin shaft of the pedestal, and the lower end of the swinging arm is provided with the pulley. A stop component arranged on the pedestal comprises a pressing spring, a positioning claw and nuts. The swinging arms can be stabilized at a first locking position and a second locking position forming an alpha angle, which is horizontal relatively to an installing plate. The alpha angle is 110 to 150 DEG, and the swinging arms and wing panels are provided with mutual fastening structures. The pulleys are hidden in the front part and the back part of the soles, and the pulleys can be used for walking. When the pulleys are spread, the pulleys can be used for sliding. The utility model has the advantages of reasonable structure, simple, convenient and applicable locking position adjustment, high stability and long service life, and is used on roller skates which are comfortably worn.