When the engine restart control of the vehicle operation method hac

The present invention relates to a method of controlling a hill start assist control (HAC) of the vehicle when the engine operation restart, the vehicle having an idle stop and a start of the automatic transmission (ISG) system. Said method comprising: restarting the engine is started by the ISG system operation and HAC; monitoring RPM of the engine; and satisfying the releasing operation in the case of HAC HAC release conditions in the RPM of the engine, and the RPM of the engine does not satisfy the conditions of release, HAC HAC case the holding operation until the release condition is met HAC.