A positioning method for a ceiling vision robot are provided. The method includes: during a moving process, a ceiling vision robot acquiring a ceiling image in real time; acquiring existing road sign distribution information according to the ceiling image; determining whether to establish a new road sign, according to the existing road sign distribution information, if so, establishing a new road sign at a acquisition position of the ceiling image, if not, not establishing the new road sign at the acquisition position of the ceiling image; and monitoring the positioning effectiveness of an existing road sign according to the existing road sign distribution information, if the positioning of the existing road sign is effective, performing positioning by using pose information corresponding to the existing road sign, if the positioning of the existing road sign is ineffective, not performing positioning by using the pose information corresponding to the existing road sign.