Electromagnetic spaces face growing threats from both naturally occurring and artificial electromagnetic pulses; however, the current protection methodologies are still far from practical needs. To address this issue, we propose an electromagnetic protection strategy that makes use of an adaptive energy selective mechanism. This strategy, carried out using electromagnetic metamaterials, provides in-band protection to electronic equipment with a high tolerance threshold and fast response. We propose several approaches to further enhance the protective performance of electromagnetic metamaterials. These include reconfigurable designs based on digital circuits and deep learning algorithms, as well as the adoption of nanoscale field-controlled devices made of two-dimensional (2D) phase transition materials and nanoelectromechanical systems. Our study can not only lead to a comprehensive protection system with superior compatibility, but also offer reliable support for maintaining electromagnetic spatial security.