The invention relates to a device and a method for treating and reusing sewage and sludge. The sewage and sludge reuse device consists of: a mixer for mixing the sewage and sludge uniformly, a rotate impact dry-crush machine for dividing the sewage and sludge supplied by the mixer into particle solid powder and water according to high-speed centrifugal force particle conflict mode and dischargingto a washer outside. The treating method consisting of the steps as follow: a pre-treat procedure for providing and mixing the sewage and sludge uniformly to improve the moisture content to 55-60%, aprocedure for dividing the sewage and sludge supplied after the pre-treat procedure into particle solid powder and water with a moisture content of 5% by the rotate impact dry-crush machine accordingto the high-speed centrifugal force, a discharge procedure for discharging the particle solid powder divided in the dry-crush procedure to the outside, and a wash procedure for dividing the water divided in the dry-crush procedure into gas and liquid and discharging the gas and liquid to the outside.