  This work proposes a simple extension of the Standard Model where a scalar
singlet and a leptonphilic scalar doublet exist. The scalar singlet could act
as thermally produced dark matter. It annihilates into leptons through
$s$-channel and benefit from the Breit--Winger resonance, so current thermally
averaged cross-section are greatly enhanced. The constraints from the isotropic
diffuse $\gamma$-ray background and correct dark matter relic abundance are
analyzed. We find that the enhanced cross-section could fit the needed
cross-section to explain the cosmic electron/positron excess.
