River channel ex-situ rapid filtering system

The utility model relates to a river channel ectopic rapid filtering system, which comprises an overflow dam, a river channel ectopic filtering belt and a river channel local widening belt, the overflow dam is arranged on the upstream of an original river channel, and the river channel ectopic filtering belts are arranged on the two sides of the extending direction of the original river channel and communicate with the original river channel through the overflow dam; the riverway local widening zone is arranged at the downstream of the riverway ectopic filtering zone, is formed by locally widening the original riverway, and is distributed on the two sides of the extension direction of the original riverway to receive flowing water purified by the riverway ectopic filtering zone. The natural purification function of a riverbed and a river bank water-soil interface is fully played, the sediment content of the river channel is greatly reduced, the water transparency is improved, and the original flood discharge