The invention belongs to the technical field of projector brackets, particularly relates to a projector installation fixing bracket. The projector installation fixing bracket comprises a main bracketand placement plates; the main bracket is of a hollow tubular structure, the main bracket is internally slidably connected with a moving rod with a rack structure, the main bracket is slidably provided with a sleeve, and the two sides of the upper portion of the main bracket are symmetrically and rotatably connected with two runners; a toothed structure is arranged on each runner; a first supportis connected on each runner, and the two runners mesh with the moving rod; a first push rod is in hinge connection between the upper part of the sleeve and the middle part of each first support; eachplacement plate is in hinge connection to the upper end of the corresponding first support; legs are hinged at the lower end of the main bracket; a second push rod is hinged between each leg and the sleeve; and a suction disc module is arranged at the lower end of the moving rod. The projector installation fixing bracket can achieve the level of the placement plates, the stable placement of the bracket, and higher stability of the bracket at the same time with adoption of the moving sleeve. The projector installation fixing bracket is simple in structure, convenient to carry and convenient andfast to assemble and disassemble when used in temporary meeting rooms.