To achieve desired jet drops, Weber number, Reynold number and Ohnesorge number, which are the three representative parameters of ink characteristics, were analyzed respectively and the new ink characteristics range applicable to the new technology area were given. An optimizing pulse was designed by establishing discrete time model method to solve the existing residual fluctuation problem caused by standard pulse in inkjet head. According to the change of curved liquid surface speed during drop injection process, the residual fluctuations in the ink cavity were compared and analyzed under the standard pulse and optimizing pulse. It was proved that the ink drops driven by optimizing pulse is more in accord with actual needs.