Cooling water purification device for shield tunneling machine construction

A cooling water purification device for shield tunneling machine construction is characterized by comprising a mixing box, a reaction box, a settling box and a filtering box which are sequentially communicated in the water flow direction; the settling tank is communicated with the filter tank through a third connecting pipe, a branch pipe is arranged at one end, close to the filter tank, of the third connecting pipe, a first block valve is arranged in front of the branch pipe of the third connecting pipe in the water flow direction, a second block valve is arranged at one end of a water outlet of the branch pipe, and the second block valve is located below the water outlet of the third connecting pipe in the height direction. An outlet pipe is arranged at the bottom of the filter box, and a third block valve is arranged on the outlet pipe. By carrying out multi-layer purification treatment on the water body, impurities and pollutants in the water body can be effectively reduced, and the cooling device is effe