Supply device with stable liquid level

The invention belongs to the field of screw detection equipment, and discloses a stable liquid level supply device which comprises a liquid container, a liquid injection pipe, a liquid outlet pipe and a liquid level balance pipe, the liquid injection pipe, the liquid outlet pipe and the liquid level balance pipe are communicated with the interior of the liquid container, the liquid outlet pipe is connected with a gushing device and provides liquid for the interior of the gushing device, and the liquid container is higher than the gushing device. The liquid injection pipe is used for inputting liquid into the liquid container. According to the technical scheme, due to the fact that the gravity principle is utilized, the influence of instability of electric power is completely avoided, in addition, due to the fact that gravity is absolutely stable, the gushing height is constant, and the stability of the technical scheme can be greatly higher than that of a precise infusion pump. According to the technical sche