We report superionic conduction in a Mg2+-containing covalent organic framework (COF) at intermediate temperature in the absence of guest vapors. A COF containing Mg2+ carriers and polyethylene oxide (PEO) chains in its channels (TPB-PEO-9-COF-Mg) was synthesized. TPB-PEO-9-COF-Mg showed superionic conductivity above 10-4 S cm-1 under dry N2 at 160 °C.