The strong coupling constant α_s is a fundamental parameter in the standard model and requires to be determined with higher accuracy. We determine α_s from static QCD potential with a new method where a renormalon uncertainty, which is an inevitable error in perturbative predictions, is subtracted from a theoretical prediction. We obtain α_s(M_Z^2)=0.1178+0.0016/-0.0015, which is consistent with the PDG result.