The invention provides a device for fixing a measuring probe onto a corona cage. The device is a cuboid-shaped fixed part which is vertically arranged. Bent parts are symmetrically arranged on the same sides of the upper end of the fixed part and the lower end of the fixed part, the middle of the other side of the fixed part is provided with a boss and a horizontal connecting rod penetrating through the center of the fixed part. The fixed part, the bent parts and the connecting rod are made of polyphenyl ether and polystyrene in a mixed mode according to the proportion of 6:4. The device is simple in structure and achieves free expansion and contraction and rotary fixation of the audible noise measuring probe in a power transmission line in the corona cage under the extra-high voltage environment on the condition that corona discharging and corona noise transmission are not affected.