A vehicle hatch dismantling device adapted to fix a hatch to allow an opening at the roof to be opened and closed for ventilation in normal times and to enable an easy detachment of the hatch in emergency such as overturn or submergence of the vehicle, making it easy for passengers to escape through the opening at the roof of the vehicle, the device having a hatch for covering an opening at the roof, a first bracket coupled to a panel underneath the hatch for vertical movement of the hatch and a toggle link mechanism secured to an area between an inner wall surface of the opening and a second bracket, the device comprising: a plurality of clamping members coupled to the first bracket for coupling the first bracket to a lower panel of a hatch; an intermittent fixing member slidably disposed at an upper side of the lower panel and coupled to the clamping member for releaseably mounting the hatch to the first bracket; and an insertion hole formed at the lower panel for allowing the clamping member to be inserted into the hatch therethrough.