In this study, a switchable multi-bit coding metasurface that is applied under a terahertz (THz) frequency by adjusting the Fermi level (EF) of Dirac semimetals (DSMs) is proposed. At a EF of 0.2 eV, a 1-bit coding metasurface can be applied in the 2.58–2.62 THz. At 0.3 eV, a 3-bit coding metasurface is realized at 1.88 THz, and at 0.05 eV, the phase of the coding units coincides in the 1.5–3 THz. So, different functions of the metasurface can be realized. The proposed coding metasurfaces has promising applications in terahertz communication.