" Everlasting Lovesickness " was a long narrative poem written by Bai Juyi, a poet of the Tang Dynasty. It mainly described the love story between Emperor Xuanzong of the Tang Dynasty and Yang Yuhuan. The whole poem expressed the author's yearning and pursuit of beautiful love, loyalty and spiritual pursuit of love by describing the emotional entanglement of the two protagonists. In the poem, Bai Juyi described the love story between Emperor Xuanzong of the Tang Dynasty and Yang Yuhuan, expressing his longing and yearning for a beautiful love. Through Yang Yuhuan's perspective, he showed her persistence and determination in love and her deep feelings for Emperor Xuanzong of the Tang Dynasty. At the same time, Bai Juyi also expressed his yearning for this kind of beautiful love, hoping to realize this kind of pure love in real life. In the poem, Bai Juyi also emphasized the loyalty in love and the spiritual pursuit of never leaving. He described the separation and reunion between Emperor Xuanzong of Tang Dynasty and Yang Yuhuan to express his persistence in love and the spirit of never leaving. He believed that true love needed to be built on the basis of loyalty and trust. Only by persistently maintaining this relationship could true love be finally realized. " Everlasting Lovesickness " was a poem that expressed the author's yearning for and pursuit of beautiful love. Through the description of the love story between Emperor Xuanzong of the Tang Dynasty and Yang Yuhuan, it showed the spiritual pursuit of loyalty and never abandoning love.