The invention discloses a mounting device for indoor suspended ceiling boards, which comprises a device main body, a bracket supporting mechanism, a bracket angle adjusting mechanism and a base, wherein the bracket supporting mechanism is connected with the bracket angle adjusting mechanism, the bracket supporting mechanism is arranged at the top of the device main body through the bracket angle adjusting mechanism, the base is arranged at the bottom of the device main body, and the device main body is driven by a lifting drive mechanism to lift vertically. The mounting device is used for mounting various boards for an indoor suspended ceiling, has small volume and light weight, is convenient to carry, is made of super-hard aluminum alloy materials, is integrally foldable vertically, and can be moved at any time and in any place during use; during operation, the board is put on the bracket supporting mechanism by only one person, then a lifting crank is started, and the board is lifted to the required height in about 10 to 20 seconds; and the angle of the bracket supporting mechanism can be correspondingly adjusted according to the angle required by the shape of the suspended ceiling to convey the board in place by one step, and the position of the board can be horizontally adjusted on all sides.