Currently, a natural speech-picking mode is badly needed in speech communication and in humancomputer interaction systems. However, speech is usually corrupted by attenuation, multi-path propagation, and various interferences before it is received, especially when there exist several speech systems and users. It is important for practical speech systems to pick the correct speech signal within complex environments. In this paper, the mechanism of auditory attention ability is simulated through a target speech-picking system in which the a priori knowledge of the target speech and interference of sound sources are used carefully to detect and improve the target speech. The technologies of microphone arrays, wake-up-words, target speech detection, speech enhancement, and dereverberation are combined in this strategy to fulfill the task of robust target speech-picking.