Aniline black is an important raw material for industrial chemical synthesis of dyes. For a long time, cotton printing and dyeing plants have directly dyed with aniline and oxidized on cotton fibers to obtain dark, firm and high-quality yuan color cloth. Aniline black is also used for cotton printing. Whether it is direct printing cloth or anti dyeing printing cloth, aniline has lower cost than dyes, black color, washing and sun resistance. It was once one of the main production processes in the 1950s.