Device for testing water flow at hole opening of underground water exploration and drainage drill hole of coal mine

A water flow testing device for a hole opening of an underground water exploration and drainage drill hole of a coal mine comprises a construction drill hole, and a limiting block is arranged at the rear end of the construction drill hole; the water conveying pipe is slidably connected to the construction drill hole and connected with the construction drill hole through a flange plate, and a rotating handle is arranged on the side wall of the water conveying pipe; the flow dividing pipe is arranged on the side wall of the water conveying pipe; the flowmeter is arranged in the middle of the water conveying pipe; the lifting mechanism comprises a gear shaft, a rack, a base, a motor and a supporting sleeve, and the rotating handle penetrates through the side wall of the supporting sleeve. The supporting sleeve is hinged to the top of the rack, the water conveying pipe penetrates through the supporting sleeve and is rotationally connected to the supporting sleeve, the height of the supporting sleeve is changed by