Henry Cowell (1897-1965), American composer in 20th century, is the first who proposed the concept of tone clusters and placed many new techniques in his piano music. Innovative music theories and unique thoughts were displayed in his compositions and critiques. For developing both new visual and audio effects of piano music, Cowell played tone clusters with arms, palms, and fists, and also played strings inside piano to give new gesture and timbre of piano. This thesis is divided into three parts besides introduction and conclusion. The first part describes the origin and development of new piano techniques in the 20th century. The second part investigates Cowell¡¦s compositional career, compositional methods and thoughts for piano music. The third part analyzes ways of performing tone clusters and strings in Cowell¡¦s solo piano pieces with new techniques. Through analyzing these particular techniques, the compositional methods and uniqueness of Cowell¡¦s piano music could be understood. In the meanwhile, the performers will pay more attention to avoid performing injuries and damaging pianos.