Considering that the maximum velocities for different types of vehicles ar e not the same and drivers may adopt different randomization brake probabilities , we pro posed a one_dimensional sensitive driving cellular automaton model for mixed tra ffic flow based on the NS model. We presented the fundamental diagrams for diff erent parameters by using computer numerical simulation, which show that the flu x is h igher than that of the NS model and the SDNS model. Moreover, some complicated b ehaviors of the model such as the metastable state and the separation of phases are also observed. Compared with the real traffic, the characters of this model are shown and analyzed.