Preliminary sedimentation tank bucket back-flushing method

The invention relates to a method for backwashing baggers of preliminary sedimentation tank which comprises the following operational steps, closing the mud valve of the previous slurry conveying unit, and closing the mud valve of the next slurry conveying unit, halting the operation of the pump package for the next mud conveying unit, and opening the backwashing valve of the previous mud conveying unit, starting the operation of the pump package for the next mud conveying unit, and injecting the mud with water into the bagger of the next mud conveying unit through the backwashing pipes and the backwashing valve.