The invention relates to a novel combustion device with a nozzle slagging prevention function. The novel combustion device comprises an air powder channel, an air powder nozzle which is formed by a middle nozzle and peripheral high-speed air nozzles, and a limiting adhesive tape which is acted by high-temperature resistant thermal insulation cotton. The peripheral high-speed air nozzles are arranged at the periphery of the middle nozzle and are supplied with air by a boiler bellows, so that a high-speed airflow ring with functions of blocking ash and slag in a boiler and avoiding slagging at the middle nozzle can be formed at the periphery of the middle nozzle, smooth supply of air and powder airflow and the combustion stability of the boiler are ensured, and the operation of the boiler isnot restricted by coal types. The heat-resistant thermal insulation cotton which is not prone to slag sticking is adopted to replace a traditional refractory casting material which is prone to slag sticking and caking, so that thermal insulation and the normal working life of the air powder nozzle are ensured, at the same time the slagging phenomenon on the surface near the air powder nozzle is also avoided, the unimpeded channeling of combustion flue gas in the boiler is facilitated, the occurrence probabilities of coking on the boiler wall, and abrasion or corrosion of the heated surface are reduced, the workload and cost of daily shutdown maintenance are reduced, the boiler operation is not restricted by the coal types, and the practicability is very high.