  Future electroweak precision measurements in the Circular Electron Positron
Collider (CEPC) project would significantly improve the precision of
electroweak oblique parameters. We evaluate the expected precision through
global fits, and study the corresponding sensitivity to weakly interacting
fermionic dark matter. Three models with electroweak multiplets in the dark
sector are investigated as illuminating examples. We find that the CEPC data
can probe up to TeV scales and explore some regions where direct detection
cannot reach, especially when the models respect the custodial symmetry.
