A slide unlocking method for a touchscreen device under a screen locking state is provided. The method includes steps of: sampling a track generated by the sliding of a user's finger on a touchscreen, and sequentially acquiring a plurality of sampling points; acquiring a first sampling point and a last sampling point of the track, and calculating a transverse sliding distance and a longitudinal sliding distance of the finger on the touchscreen; and unlocking the touchscreen when the transverse sliding distance is greater than or equal to a first preset distance and the longitudinal sliding distance is less than or equal to a second preset distance; otherwise, keeping the screen in the lock state. In this way, the present invention increases the degrees of freedom of a user's operation, so that a user can conveniently perform unlocking in a special usage scenario.