Spin-orbit-coupled ultracold atom system becomes an important platform to simulate Zitterbewegung. Current experimental study of Zitterbewegung is in a two-component atomic system, while the existed three-component theoretical study on spin-orbit coupling is difficult to realize in experiments. In this paper, based on the experimentally realizable three-component spin-orbit-coupled system, we analyze the Zitterbewegung and reveal that the Zitterbewegung has many oscillation frequencies. In the presence of harmonic trap potentials, Zitterbewegung oscillation possesses more rich physical characters.