An advanced driving assistance system (ADAS)-linked active hood apparatus for always-on operation is provided. The apparatus includes a rotary arm that is fixed to a hood of a vehicle, a stationary bracket fixed to a vehicle body, and a rotary bracket that rotates upward and downward by applied rotation force. A first link interconnects the rotary bracket and the stationary bracket. A motor unit is integrally connected to the rotary arm and applies driving force to the rotary bracket. A controller receives driving information of the vehicle via an ADAS and sets a pop-up height of the hood. The motor unit then performs pop-up and restoration of the hood when a collision is expected based on the received driving information.