Under the impetus of wireless communications, metamaterials have attracted considerable attention due to their superior merits of free manipulation of electromagnetic waves and easy integration. However, most efforts to date are mainly focused on the modulation of wave information or recognition of wave intensity, while the frequency detection is rarely explored. Here, a spoof localized surface plasmon (SLSP) structure is proposed to realize reconfigurable frequency detections. By switching the bias voltage applied to the varactor, the resonance frequency of SLSP can be controlled dynamically from 1.95 to 2.35 GHz. The SLSP‐based waveguide has a relatively high quality factor due to the strongly localized field confinement. Reconfigurable frequency detection is demonstrated experimentally by monitoring the output voltage of the introduced detector. The measured and simulated results are in good agreement. This work will hold promising applications in wireless communication and sensing systems.