Ground-Based Augmentation System (GBAS) is advancing steadily worldwide and is expected to become the core of future aviation navigation systems. Among its components, determining the location of GBAS ground stations plays a decisive role in the implementation and formal operation of the entire system. However, there is currently a lack of a highly efficient and flexibly deployable GBAS site selection device. Therefore, a portable GBAS site selection device is proposed, mainly introducing the device composition, working principle, functionality and implementation evaluation methods, which provides an effective solution for rational GBAS site selection and helps promote the application and development of GBAS in the field of aviation navigation. Taking the Category I GBAS as an example, the study conducted field measurements, comprehensive analysis, and evaluation of preliminary GBAS site selection locations at a certain airport using the device, providing essential technical conditions for the operation of the GBAS system.