A rotational positioning structure comprises a rotating shaft, a rotating body and a rotating arm. The rotating shaft is fixedly connected with the rotating body which is held in the rotating arm and can rotate in the rotating arm; the rotational positioning structure also comprises at least one friction block which is fixedly arranged on the inner surface of the rotating arm; and one surface of the friction block is an internally concave spherical surface which coordinates with the outer surface of the rotating body. The rotational positioning structure further includes a sleeve cladding the outside of the rotating arm. The sleeve is provided with a through hole and a notch cutting through the through hole so as to make the sleeve to broken off from the notch. Two opposite sides of the through hole periphery are provided with a pair of snap joints which are arranged on the rotating arm. The rotational positioning structure has less wear and can achieve good positioning effect.