A sludge recycling treatment system of an urban sewage plant includes solar sludge drying and sludge roasting and activated carbon manufacturing devices. The solar sludge drying device has a sealing box, flat plate conveyor belts, and a conveyor belt traction device. The sludge roasting and activated carbon manufacturing device has a rotary kiln and feeding, conveyor, discharging, and flue gas recycling apparatuses. The flat plate conveyor belts are stepped and concave-convex manufactured from stainless or anti-corrosion carbon steel. Sludge roasting and activated carbon manufacturing is implemented mainly by a rotary kiln to heat a rotary drum wall therein to heat materials. The kiln has automatic feeding and discharging apparatuses. Harmless treatment and resource utilization of urban sludge converts the sludge from waste to wealth, and fully utilizes solar energy to reduce energy consumption during sludge treatment. During production and operation, no reagent is needed, and no secondary pollution is caused
