The gravity gradient data is used in the navigation system through the Unscented Kalman Filter (UKF) to study the feasibility and superiority of the gravity gradient aided navigation system.The paper first analyzes how to simulate the gradiometer signal with the given gravity gradient map dataand presents a method that uses an interpolation method first and then adds noise to this data with a final lowpass filterer operation.According to the necessity of UKFthe system dynamics of the gravity gradient aided navigation system is providedand how to use the UKF in this model is described.At the end of the paperthe simulation analysis is given to the gravity gradient aided navigation systemmainly through the comparative study of no external aided and the gravity gradient aided navigation systemto demonstrate the availability and feasibility of applying the gravity gradient data to the navigation system.