A control method is provided for controlling an internal combustion engine for a vehicle configured to engage a lockup clutch during a fuel cut, and to decrease a lockup hydraulic pressure at a fuel cut recovery to bring the lockup clutch to a slip engagement. The control method includes estimating a torque of the internal combustion engine generated by the fuel cut recovery when a fuel cut recovery condition is satisfied. The control method further includes decreasing a decrease amount of the lockup hydraulic pressure as the torque is greater.