His calligraphy art follows the calligraphy of the sages (Erwang, Yan, Liu, Ou, Zhao), explores the hidden meaning, studies the degree of keeping black and white, studies the law of rigid and flexible changes, reveals the charm of yin and yang copulation, and integrates the techniques of line, grass, official script and seal script to form a unique style.
His seal cutting was personally taught by Gao Shigu, a disciple of Qi Baishi, and realized the life level of carving art on the stone, hiding the great feelings of heroism, change, agility and charm in the square inch, and his style was unique.
In 2009, for the 60th anniversary of the founding of People's Republic of China (PRC), he created "The Picture of China's Harmonious Prosperity", which was deeply appreciated and favored by party and government leaders in cultural circles, celebrities and friends in calligraphy and painting collections. Domestic media believe that the art of Zhang Demao's works originates from life and is higher than life, and has entered a wonderful state of agility and purity. He controls the tension of pen and ink while talking and laughing, and the feeling of moving everything is more and more vivid on paper, so he is worthy of being a painter of the strength school of contemporary Chinese painting in China.