Team cognition is a result of emergence from individual cognition. The emergence of team cognition is determined by the sum of individual-level cognitive properties, together with the interactions between team members. We first elaborated the concept of team cognition, and described three key features of emergence — namely, organization-dependence, the absence of intentional design and multiple realizability — as well as two ideal forms of emergence, including composition and compilation. Then, according to the perspective of collective information processing, the paper built up a model of team cognition emergence that covered four phases of individual knowledge base, the distribution of team knowledge, communication and interaction, and the emergence of team cognition. Finally, as a phenomenon of emergent team cognition, transactive memory system was discussed in order to provide further explanation.