High-performance terahertz wave detectors at room temperature are still urgently required for a wide range of applications. The available technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, complicated structure, and high noise equivalent power (NEP). Here, we have demonstrated a Weyl semimetal surface plasmon-enhanced high-performance terahertz wave detectors which are based on microdisk array deposited WTe 2 nanofilm epitaxially grown on GaN substrate for room temperature operation. With the microdisk array combined the WTe 2 layer, strong terahertz wave surface plasmon polaritons can be generated at the WTe 2 –air interfaces, which results in significant improvement in detecting performance. For the 40 μm diameter microdisk array, a detectivity ( D * ) of 5.52 × 10 12 cm Hz 1/2 pW −1 at 0.1 THz is achieved at room temperature. In addition, the responsivity ( R A ) of 8.78 A W −1 is also obtained. Such high-performance millimeter and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing.