The utility model relates to the field of building construction, and discloses an adjustable safety hanging bracket for operation in a hole. The safety hanging bracket comprises clamping rods and half-range hanging brackets, the half-range hanging brackets are arranged on the two sides respectively, each half-range hanging bracket comprises a hanging component and a pedal rod, the pedal rods are connected to the bottoms of the hanging components to form an L-shaped structure, the pedal rods on the two sides are oppositely arranged towards the inner sides of the half-range hanging brackets, andthe ends of the pedal rods on the two sides are overlapped and connected through adjustable connecting pieces. The hanging component is provided with at least two connecting positions in the verticaldirection, and the clamping rod is arranged on the outer side of the half-range hanging bracket and connected to the connecting positions of the hanging component in an adjustable connecting mode. The safety hanging bracket can realize horizontal telescopic change and height lifting adjustment, so that the safety hanging bracket is adaptive to holes with different diameters and different depths,material waste and labor waste caused by remanufacturing a set of safety hanging bracket for holes with different sizes are avoided, the construction cost is saved, and the operation efficiency is improved.