Built-in comprehensive drying and incinerating system for sludge and drying and incinerating method for sludge

The invention provides a built-in comprehensive drying and incinerating system for sludge and a drying and incinerating method for the sludge. According to the built-in comprehensive drying and incinerating system for the sludge and the drying and incinerating method for the sludge, hot smoke generated after incineration is used for drying the sludge, a middle circulation link is omitted, and bad smell escaping is avoided. The built-in comprehensive drying and incinerating system comprises a rotary kiln, a drying box, a secondary combustion chamber and a feeder. A plurality of conveying belts arranged in parallel from top to bottom are arranged in the drying box. The bottom of the drying box is provided with a drying box discharging port corresponding to the discharging end of the conveying belt on the bottommost layer. The drying box discharging port is communicated with a feeder feeding port through a discharging hopper. A rotary kiln air inlet is formed in a kiln head of the rotary kiln. A rotary kiln air outlet is formed in a kiln tail of the rotary kiln. The rotary kiln air outlet is communicated with a secondary combustion chamber air inlet. A drying box air inlet is formed in the bottom of the drying box. A drying box air outlet is formed in the top of the drying box. A secondary combustion chamber air outlet is communicated with the drying box air inlet.