In this paper, the stochastic event-triggered multiple targets formation tracking (MTFT) problem is studied for a group of second-order agents with incomplete measurement. It aims at driving agents to reach the desired formation and track the convex hull of multiple dynamic targets. By using the high-order sliding mode observer and velocity filter, a MTFT algorithm is designed without the requirement of velocity and acceleration measurement. In addition, the stochastic event-triggered strategy is involved to reduce the communication consumption among agents. Finally, a numerical example is given to illustrate the effectiveness of the stochastic event-triggered MTFT algorithm.