The main theme of the poem is the exaggerated poem "This trip is more difficult than climbing the sky", singing and sighing. First of all, myths and legends are introduced into the poem, and through the imagination of the fear of birds and beasts and the sigh of pedestrians, the rigor of Shu Road is highlighted. Then imagine the terrible environmental atmosphere that pedestrians feel on the Shu Road, highlighting the danger and fear of the Shu Road. Finally, from the description of natural conditions to the hints of historical lessons, there are hidden concerns about the political situation in central Sichuan.
This poem uses exaggeration, metaphor, rendering and suggestion. From ancient times to the present, the scenery is far and near, and the emotion goes from shallow to deep, which fully shows the difficulty of Shu Dao. However, due to the heroic spirit of the poet, readers are not afraid of the dangers of Shu Road, but appreciate the magnificence of mountains and rivers, and the hints in the poem also enrich the connotation of the poem. Therefore, Yin Yao praised this poem as "strange and strange, and it is rare to return it from the poet." (He Yue Ying and Ji Ling).