Cheng Gai, whose courtesy name was Zhengbo, hailed from Meishan in modern-day Sichuan province. He belonged to a distinguished scholarly lineage, notably as the maternal grandson of Cheng Zhengfu, who was a cousin of the monumental literary master Su Shi. During the Chunxi era, Cheng Gai traveled extensively to the imperial capital of Lin'an. Despite his considerable literary gifts, he remained without prominent official rank or bureaucratic office well into the reign of Emperor Guangzong. His life was thus defined largely by scholarly pursuits and poetic composition rather than high political station.
As a notable contributor to the Song lyric tradition, Cheng Gai specialized in the Ci poetic form. His style is characterized by a melancholic grace, delicate lyricism, and emotional intensity. Scholars of classical literature frequently highlight his surviving collection, known as the Shuzhou Ci. Within this corpus, he demonstrated a masterful command of musical meter and emotional nuance, capturing the subtle vicissitudes of human sentiment, seasonal melancholy, and scholarly wandering.
Cheng Gai's worldview reflects the refined aesthetic sensibilities typical of the Sichuan literati of the Song dynasty. Influenced by his familial ties to the intellectual circles of Su Shi, his writings balance a deep engagement with emotional introspection and a detached, poetic appreciation of nature. Without the burden of high court office, his artistic persona remained that of an itinerant scholar-poet, finding solace in artistic creation and the expressive potential of lyric verse.
Although he did not achieve high bureaucratic renown during his lifetime, Cheng Gai's literary legacy endured through his contributions to Southern Song Ci poetry. Preserved within historical anthologies and critical studies of classical verse, his works are valued by modern and traditional scholars alike for illustrating the stylistic evolution of the lyric genre during the transition into the late Southern Song period, offering valuable insights into the era's refined poetic culture.