Flight test of civil aircraft can truly verify aircraft performance, but it is high-risk. For civil aircraft flight test, especially subjects related to handling qualities, the aircraft's weight and center of gravity are quite sensitive. Therefore, it is necessary to consider flight tests under different weight and center of gravity combinations. However, not every civil aircraft test aircraft is equipped with a safe water ballast system, so it is necessary to consider adjusting the center of gravity through fixed ballast to ensure that the flight test requirements are met. Based on the characteristics of civil aircraft, this paper proposes a method to arrange the weight and position of fixed ballast for civil aircraft, with analyzing the characteristics of fixed ballast for civil aircraft flight test. Focusing on flight tests, this method ensures flight test safety and meets flight test requirements while minimizing the total weight of fixed ballast to achieve efficient testing.