The invention discloses a full-automatic sheep weight and size measuring device and a measuring system thereof, the device comprises a bottom plate, grid plates, comprehensive rods and vertical rods, wherein the top of the bottom plate is provided with two groups of grid plates arranged front and back, the tops of the two groups of grid plates are provided with the comprehensive rods, and the top of the bottom plate is provided with a plurality of groups of vertical rods arranged front and back. A notch is formed in the top of the bottom plate, a weighing device is installed on the bottom wall of the notch, and a protective pad is installed on the top of the weighing device. A groove is formed in the top of the bottom plate, an intercepting strip is installed on the bottom wall of the groove, two sets of groove holes arranged front and back are formed in the outer wall of the side, close to the intercepting strip, of the bottom plate, and two sets of springs arranged front and back are installed on the outer wall of one side of the intercepting strip. According to the device, the body height, the body width, the body length and the body weight of the sheep can be measured, meanwhile, deviation is small in the measuring process, finally obtained data are accurate, the weighing device in the device is detachable, and then maintenance is convenient.