The utility model relates to a spirit level installation support bracket, including first layer board, set up respectively in the second layer board and the mounting panel at first layer board both ends, be provided with a plurality of fixed orificess on the mounting panel, first layer board is provided with first mounting hole, be provided with first nut in the first mounting hole respectively, adjusting screw with first nut screw -thread fit, the left end of second layer board is provided with the second mounting hole, be provided with the second nut in the second mounting hole respectively,the 2nd adjusting screw with second nut screw -thread fit, the right -hand member of second layer board is provided with the third mounting hole, be provided with the third nut in the third mountinghole respectively, the 3rd adjusting screw with third nut screw -thread fit. Pass through mounting panel fixed connection during the use to the corresponding installation mechanism on, the surveyor'slevel is placed on first layer board and second layer board, only need rotate an adjusting screw, the 2nd adjusting screw and the 3rd adjusting screw respectively, alright operate in order conveniently to carry out the leveling. The first -aid safety helmet has a simple and reasonable structure.