Abstract: The drop tower is an important ground-based experimental facility for simulating the microgravity environment in space. During its free fall in the drop tower, the stability of the drop capsule’s flight attitude is closely related to the position of the drop capsule’s centroid. Ensuring the coincidence of the drop capsule’s centroid with its structural centerline is the key to maintaining the ideal flight attitude of the drop capsule, and then to ensure the safety of its recovery and to suppress the disturbance of residual microgravity inside the drop capsule caused by the release and subsequent changes of flight attitude. Presently, the method of distance measurement by rotating the drop capsule suspended by a single wire is used for adjusting the drop capsule’s centroid in the drop tower Beijing. It has drawbacks such as high operational difficulty, long time-consuming and the complicated procedures. A new method, thus, is proposed for calibrating drop capsule’s datum plane and quickly adjusting the drop capsule’s centroid. It’s shown by actual operations that the new method can greatly simplify the process of adjusting the drop capsule’s centroid, significantly shorten the preparation time, and then obviously improve the efficiency of drop tower experiments.