We study the recent e± cosmic ray excess reported by DAMPE in a Hidden
Valley Model with lepton-portal dark matter. We find the electron-portal can
account for the excess well and satisfy the DM relic density and direct
detection bounds, while electron+muon/electron+muon+tau-portal suffers from
strong constraints from lepton flavor violating observables, such as μ→3e. We also discuss possible collider signatures of our model, both at the LHC
and a future 100 TeV hadron collider.Comment: invited by Science China, accepted versio