Du Fu saw that the mountains and rivers were still broken and ruined, but the land was desolate in spring. At this time of homesickness in adversity, he couldn't help feeling deep sorrow and emotion. The poet showed patriotism in this poem. The whole poem expresses the poet's feelings of worrying about the country, hurting his time, homesickness, self-pity and missing his loved ones. The central idea of this poem is: by describing the desolate scene of Chang 'an in the An-Shi Rebellion, it expresses the poet's feelings of worrying about the country and homesickness, and reflects the poet's desire for peace and happiness.