The utility model provides a portable device for measuring a sheep body size. The invention relates to the technical field of sheep body scale determination. The device comprises a bottom plate, fourthreaded holes are symmetrically formed in the center of the bottom plate; a supporting rod is arranged in the threaded hole; the lower end of the supporting rod is in threaded connection with the threaded hole; transverse plates are arranged on the supporting rods on the front side and the rear side; The left end and the right end of the transverse plate are connected with the supporting rods through detachable first bolts correspondingly. sleeves are arranged on the inner sides of the left end and the right end of the transverse plate; A rotating column is arranged on the outer side of the door body, the rotating column is sleeved with the sleeve, a hanging ring is arranged on the supporting rod, a spring is arranged on the door body, a hook connected with the hanging ring in a hanging mode is arranged at the inner end of the spring, a sheep can be fixed when the sheep measure a body scale, the measuring accuracy and the measuring efficiency are improved, and the door is detachable and convenient to carry.