Gao was particularly renowned for ushering caoshu, the cursive script, into a new realm through his own innovative approach. He is hailed in calligraphy circles as a "modern caoshu sage", partly owing to his mastery of the unique zhangcao style, a preliminary form of the cursive caoshu script, but blending the strokes of the clerical lishu script.

Wu Hongliang, director of Beijing Fine Art Academy, says Gao's calligraphy is grounded in his masterful command of the solemnity of zhangcao script, but, meanwhile, is imbued with the reckless temperament of the writings of father and son Wang Xizhi and Wang Xianzhi, the celebrated fourth-century calligraphers. Gao's long-term commitment to the studies of these ancient masters allowed him to create an even more artistic, highly expressive style of his own in the later stages of his life.

Gao is also respected for his rigorous approach toward academic study. A famed example is his avid involvement in an academic discussion in the 1960s pertaining to Lanting Xu (Preface to the Poems Composed at the Orchid Pavilion), a great piece by Wang Xizhi. Gao showed critical thinking, intensive learning and self-confidence, even when he had opposing views to experts in the field that were senior to him.

Gao fulfilled his commitment to carrying on the cultural lineage through cultivating a younger generation of scholar-calligraphers. He would invite students to his home, and give lectures on Chinese classic texts and art.

In 1987, an exhibition of Gao's work, in memory of the 10th anniversary of his passing, was held at Jiangsu Art Museum, in the provincial capital Nanjing, where Gao lived for decades. Lin Sanzhi, master calligrapher and a close friend of Gao, visited the show and, afterward, the 89-year-old wrote that, "Gao lived up to the fulfillment of art, and led a life of distinction and integrity".