In color printing process, a black plate was added to compensate dark shortage of printing image in general. A black plate generation method based on Neugebauer Equation was proposed. Part of color blocks of IT8. 7 / 3 were selected as the sample, and the XYZ values of the sample were transformed into corresponding CMY dot area rate through Neugebauer Equation. Value of relevant parameters was determined to get the black plate value by using the calculation formula of black plate. The experiment results showed that the black plate generation method has certain reliability and practicability, which has reference value and theoretical significance for color separation in printing and black plate generation.