To address the low efficiency in checking the elevation of the control point，this paper studies the principles and data processing methods of the Beidou ground-based augmentation system and the high-resolution EGM2008 gravity field model（1′ × 1′）. By integrating the above two technologies，this paper puts forward a specific process and an operation method for quickly obtaining the elevation of the point to be determined and verifies the method through engineering examples. The results show that the error is less than 5 cm regarding the external coincidence accuracy obtained by this method. It can effectively identify the availability of existing results and distinguish the type of an elevation system. The results of the proposed method are accurate and reliable，and the operation is convenient and efficient. In addition，the method can reduce the costs，which has a reference value for similar port and waterway engineering.