Abstract: The present invention discloses a fully foldable four-wheel walking aid, comprising a left frame and a right frame which are connected by an X-shaped frame, wherein each of the left frame and the right frame includes a wheel frame, an armrest adjustment frame, a fixed base and a rotary movable base. The armrest adjustment frame, the rotary movable base and the fixed base are connected by a rotating shaft screw; and a through hole of armrest adjustment frame is provided in the armrest adjustment frame, rotary movable base is provided with a through hole of rotary movable base, and fixed base is provided with a through hole of fixed base. An open space is formed by the through hole of armrest adjustment frame, the through hole of rotary movable base and the through hole of fixed base, and an elastic pin having recovery capability is provided in the open space.