The invention discloses a finger rotating and moving device of a configuration-changeable robotic gripper and a working method thereof. A first finger is used for realizing self opening-closing motions, structures and installation modes of a second finger and a third finger are same, the second finger and the third finger are used for realizing self opening-closing or realizing rotation and movement on finger positions; a planetary gear in a drive transmission mechanism is arranged between an internal gear and fan-shaped gears and driven by the internal gear and the fan-shaped gears, the two fan-shaped gears are arranged on a palm frame through a pin roll so as to realize that the two fan-shaped gears rotate opposite to the palm frame around the pin roll, and one ends of the two fan-shaped gears form a quadrilateral mechanism through mechanical connection by using pins together with two connecting rods. In the working method, the fingers of the configuration-changeable robotic gripper can change the gripping configurations according to sizes and shapes of objects under the drive of a motor to increase the stability of gripping so as to realize rotation to ensure that the fingers are switched among a parallel gripping state, a three-finger centering pinching state and a two-finger opposite-pinching state and realize revolution and the adjustment on finger positions.