The invention discloses a positioning device, and relates to the technical field of carving positioning. The positioning device comprises a bottom frame for supporting to-be-machined parts. Multiple supporting parts are arranged on the top of the bottom frame, the supporting parts are rotationally connected with pressing parts, and the pressing parts are used for clamping the to-be-machined parts.The multiple pressing parts with adjustable pressing directions are used for pressing the to-be-machined parts, the device can position and clamp flat to-be-machined parts, and meanwhile can positionand clamp hook-face to-be-machined parts, and the practicality of the device is improved. The positions among a first bottom frame body, a second bottom frame body, a third bottom frame body and a fourth bottom frame body can be adjusted to meet the positioning requirements of boards with different sizes, and the practicality of the device is further improved.