"Out of the Fortress" should be written by Wang Changling when he went to the Western Regions in his early years. "Out of the Fortress" is an old Yuefu title. The era in which Wang Changling lived was at the height of the Tang Dynasty. During this period, the Tang Dynasty repeatedly won foreign wars, and the nation's self-confidence was extremely strong. Therefore, the works of frontier poets can often reflect an impassioned and upward spirit, and the ability to defeat the enemy. strong confidence. At the same time, frequent frontier fortress wars have also overwhelmed the people and yearned for peace. "Out of the Fortress" reflects the people's desire for peace. Du Fu's "War Chariots" of the same period can be used as a reference. Frontier poetry is a product of the times, and it is also the work that best reflects the rise and fall of a country's fortunes. Poetry critics often praise "the sound of the prosperous Tang Dynasty", and frontier fortress poetry is a basic aspect of the content of "the sound of the prosperous Tang Dynasty". The rise of the theme of frontier fortress poetry is closely related to the expansion of the poets' life scope. From the frontier fortress poems, we see that the poet's horizons have broadened, the artistic conception of the poems has expanded, and the content of the poems has become even more colorful. There is the desire to build industry: "It is better to be a centurion than a scholar" (Yang Jiong); there is the passion to serve the country: "I vow to become famous and serve the country, but I am ashamed to talk about my merits" (Zhang said). Many poets have lived in military camps outside the fortress for many years, such as Gao Shi, Cen Shen, Li Yi, etc. The contents of their frontier fortress poems cover almost all aspects of frontier fortress life: some write about the homesickness of soldiers on expedition and the separation and resentment of their wives at home; The hardships of life outside the Great Wall and the cruelty of successive battles; some reflect the emperor's dissatisfaction with the military expansion of the border and the resentment against the generals who took advantage of their power; some describe the nostalgia for hometown and relatives who have been garrisoning the border for a long time; some are surprised at the completely different feeling in the extremity beyond the Great Wall. The scenery of the Central Plains... When we read these poems, we must be able to distinguish the subtle differences in the ideological content of each poem. For example, Cen Shen's frontier fortress poems are based on the heroic spirit of generous service to the country and the optimistic spirit of not fearing hardship, and describe more of the colorful life of the frontier fortress. He also wrote some poems about being nostalgic for his family in the frontier fortress, such as "Meeting the Envoy Entering the Capital" that was passed down to future generations: "Looking eastward from my hometown, the road is long, and my sleeves are full of tears. We will meet soon, and there is no pen and paper, so I can pass the message with you. May you be safe." Although the matter is small, the affection is profound. At the same time, we must also appreciate the various contradictions that animate in frontier poems: the contradiction between generous service and long-term homesickness; the contradiction between passion for defending the country and hard life; the contradiction between hatred of mediocre generals and dedication, etc.