The invention relates to an incineration treatment method of municipal sludge and a device thereof. The method comprises the steps of directly mixing powdered coal with average particle diameter of 75 to 90 micrometers, municipal sludge with water content of 95 wt percent and water according to the mass ratio of 60:25:15, then stirring for two times and filtering to manufacture finished sludge water-coal-slurry, directly adopting a screw pump for pressurizing, feeding the sludge water-coal-slurry into a sludge water-coal-slurry atomizing nozzle, and simultaneously feeding compressed air and primary air into the atomizing nozzle to ensure that the sludge water-coal-slurry is injected into a combustion chamber in a good spray pattern. Generated high-temperature flue gas is discharged into atmosphere after heat is recycled by a waste-heat boiler, and clinker is recycled. The device mainly consists of a coal grinding mill, a powder storage bin, an agitator tank, a first filter, a first screw pump, a storage tank, a second filter, a second screw pump, a combustion chamber, a waste-heat boiler and a bag-type dust collector. The disadvantages in the conventional sludge incineration method that the process is complex and the energy consumption during the sludge drying is high are overcome, and the low pollution emission of the flue gas and the comprehensive utilization of the clinker are realized.