In order to explore how to get agility indices with a simulator , the transient agility and functional agility metrics of the third generation fighter have been simulated. Then the simulation results , the calculation ones and the corresponding simulation results of F -18HRAV have been compared. The results show that it is very difficult to get agility indices with simulation method because of the very short time of agility control input and the difference of every time's control input. And the control inputs of the agility metrics should designed again in order to make the value of simulation results greater.