Spaceborne laser altimeters are active remote sensing instruments, currently offering the highest accuracy in spaceborne elevation measurements. The latest generation of single-photon laser altimeters provides extremely high spatial resolution and precision, delivering detailed surface elevation profiles and representing a key direction in future development. However, the increased along-track measurement density and the use of highly sensitive single-photon detectors result in a data volume several orders of magnitude higher than that of traditional systems, imposing significant burdens on satellite data transmission and processing. To address this issue, a footprint prediction method based on position iteration is proposed, followed by the development of a dynamic range gate prediction algorithm to enable more effective data filtering. Validation using ICESat-2, the only currently operational single-photon laser altimetry satellite, shows that in a test area with a maximum terrain relief of 606 m, the predicted range gate（without margin）fullly covers of ground elevation with dynamic widths ranging from 468 m to 704 m. The algorithm’s prediction time remains under 0.8 s. These results demonstrate the algorithm’s strong adaptability and computational efficiency, providing technical support for future Chinese satellite missions using single-photon laser altimetry.