Disclosed is an external fixing device for treating a fracture of a calcaneal, comprising an external fixing plate (1) and a plurality of screws (2). A shape of the external fixing plate (1) is adapted to match a contour of the calcaneus. The external fixing plate (1) is provided with a plurality of threaded holes (12) and a hollow portion (11) that extends through the external fixing plate (1) along a thickness direction of the external fixing plate (1). One end (21) of each of the screws (2) matches one of the threaded holes (12) by thread fit, and the other end (22) of each of the screws (2) is suitable to screw into the calcaneus. The external fixing device is of a relatively light weight and is convenient to operate. Besides, it achieves a good fixing effect with little damage.