Can bow like a full moon, look northwest, shoot Sirius, Sirius is of course the main invasion and main battle in astrology. Bow carving is a sagittal star, a bow and arrow star formed by three stars in the middle of Orion and other stars around it. The three stars in the middle, the arrows, extend in a straight line to the northwest, which is Sirius. In the starry sky, it is a scene of shooting Sirius with a bow to the northwest. This allusion used by Su Shi is not the earliest. Qu Yuan's "Shooting Sirius with a Long Arrow" in "Dong Jun" refers to the State of Qin in the northwest of Chu. At that time, the rulers of the Northern Song Dynasty were weak and often harassed by the surrounding ethnic minorities. Xixia is one of them. Located in the northwest of the Northern Song Dynasty, now Ningxia, Gansu, with Yinchuan as its capital. Among them, "looking at the northwest and shooting at Sirius" is an allusion to the ancient enemy Xixia Kingdom. At that time, the author was demoted to the state secretariat, but he still wanted to serve the country, so he wrote this poem on a hunting trip to express his patriotism.