To solve the problem of time-varying formation control of the second-order multi-UAV system, a consensus distributed controller is designed by using the event-triggered function, so that the multiple UAVs can form a time-varying formation.The Laplacian matrix is decomposed considering its special properties.The formation problem is simplified to the problem of asymptotic stability of low-order systems.The algorithm of controller design is given.Linear Matrix Inequality (LMI) and Lyapunov function are used to prove the effectiveness of the algorithm under the given event-triggered function.It is proved that there is no Zeno phenomenon in the time sequence of the given event-triggered function.The motion of the multiple UAVs system is simulated in 3D space.The results show that the multiple UAVs can form the desired time-varying formation under the effects of the designed controller, which effectively saves communication bandwidth and computing resources.