  The top quark Yukawa coupling ($y_t$) can be modified by two dimension-six
operators $\mathcal{O}_H$ and $\mathcal{O}_y$ with the corresponding Wilson
coefficients $c_H$ and $c_y$, whose individual contribution cannot be
distinguished by measuring $y_t$ alone. However, such a degeneracy can be
resolved with Higgs boson pair production. In this work we explore the
potential of resolving the degeneracy of the unknown Wilson coefficients $c_H$
and $c_y$ at the 14~TeV LHC and the 100~TeV hadron colliders. Combining the
information of the single Higgs production, $t\bar{t}h$ associated production
and Higgs pair production, the individual contribution of $c_H$ and $c_y$ to
$y_t$ can be separated. Regardless of the value of $c_H$, the Higgs pair
production can give a strong constraint on $c_y$ at the 100 TeV hadron
collider. We further show that it is possible to differentiate various $c_y$
and $c_t$ values predicted in several benchmark models.
