Pollution discharging device of slag discharging system of waste incineration power plant

In order to solve the problems existing in the prior art, the blowdown device of the slag discharging system of the waste incineration power plant comprises a slag discharging machine box body, a water supplementing box and a connecting pipe between a slag discharging machine and the water supplementing box, and water in the water supplementing box flows into the slag discharging machine box body through the connecting pipe. Different from the prior art, a collecting cone hopper is further arranged at the bottom of the water replenishing tank to collect sludge deposited in the water replenishing tank, a blow-off pipe is further installed at the bottom of the collecting cone hopper, a blow-off valve is further arranged on the blow-off pipe, and sludge in the water replenishing tank can be discharged by opening the blow-off valve at regular intervals. Sludge and impurities cannot be deposited in the water supplementing tank and the communicating pipe for a long time, and the problem of blocking of the communica