  We propose a hybrid continuum surface force (CSF) formulation to model the
interface interaction within the three-phase volume of fluid (VOF) method.
Instead of employing the height function globally, we compute the curvature
based on a smooth fraction function near the region of the triple contact line.
In addition, we apply the isotropic finite difference method to calculate
derivatives, and the current scheme readily accommodates adaptive mesh
refinement, greatly enhancing efficiency. We rigorously validate the hybrid CSF
using two benchmark problems that have received limited attention in previous
studies of the three-phase VOF method. Using the hybrid CSF method, we
accurately predict the behavior of a liquid lens under specific surface tension
ratios. Furthermore, the simulation results of the equilibrium morphology of
two contacting droplets are consistent with the theoretical expectations.
