In the gravity aided inertial navigation system,the observing information exists lag due to the gravimeter output delay,conventional EKF algorithm is difficult to ensure the accuracy of filtering.To solve this problem,the mathematical model for EKF is established, in which measurement information is the difference between gravity anomaly measured by gravimeter and the values in the gravity anomaly map according to INS.The delay time of gravimeter is calculated by using of Etvs effect,Based on which,an algorithm of time delay compensation is proposed and applied to the gravity aided inertial navigation system.The simulation results show that the algorithm can effectively reduce adversely affect by the time delay and improve the position accuracy of gravity aided inertial navigation system.