With the continuous development of 6G technology, terahertz radar and integrated sensing and communication are gradually becoming important research directions in the field of electronics and information. Programmable metasurfaces, with their advantages of being lightweight, conformable, and dynamically tunable, exhibit a high degree of freedom in terahertz beam manipulation, and thus hold significant application potential in communication, imaging, and radar. Starting from the design theory of programmable metasurfaces loaded with semiconductor components, a GaAs varactor suitable for high-frequency applications is selected, a 1 bit digital coding metasurface is constructed, and its sub-terahertz electromagnetic response and beam manipulation performance are characterized. The results show that the metasurface array has wide-angle dynamic beamforming and beam scanning capabilities in the W-band, with experimental results matching well with simulations.