The utility model discloses a processing system is collected to sedimentation tank dross, including floating slag pit, two sink the output mouth of pipe that connects the sediment to fight in the ponds pass through the dross output tube and the slag pit intercommunication floats, its characterized in that: it has the overflow pipe to put fixed mounting at the middle and upper position of the poolwall that floats slag pit, still include the submersible sewage pump, this submersible sewage pump fixed mounting is in the bottom of floating slag pit, and the inlet pipe of the flocculation agitatortank of the output of this submersible sewage pump in through dehydration machine room among pipeline and the sewage treatment plant is connected, the flocculation agitator tank is arranged in infeeding mud for the belt filter -pressing hydroextractor in the sewage treatment plant dehydration machine room. The utility model discloses a processing system is collected to sedimentation tank dross has simple structure, easy implementation, and effectual and more thorough advantage is got rid of to the dross.