The invention belongs to the technical field of valve machining, especially relates to a leakage-proof detection device for valve machining. For the problem of the detection accuracy, the following solution is presented: the device comprises a transparent detection box motors are arranged on the two sides of the outer wall of the bottom of the transparent detection box, output shafts of the motorsare connected with rotating rods through couplers, stirring rods distributed at equal intervals are arranged on the two sides of the outer wall of each rotating rod, the specifications and sizes of the stirring rods are different, the sizes of the stirring rods are gradually reduced from top to bottom, and an inverted horn-shaped structure is formed. According to the invention, the motors, the rotating rods, the stirring rods and the stirring blades are arranged; the sizes of the stirring rods are gradually reduced from top to bottom, the inverted horn-shaped structure is formed, the uneven stirring rods can form vortexes and water waves with different sizes, water flow impact with different sizes can be conducted on the valve, the situation that the valve is impacted by water flow can besimulated, and leakage-proof detection can be conducted on the valve more accurately.