Dry powder solid fuel gasifying technology and system with waste heat recovery

The invention relates to a dry powder solid fuel gasifying technology and a system with waste heat recovery and aims at solving the problems of the existing equipment such as complicated structure, high equipment investment and operation cost, easy dust deposition of system, low stability and environmental pollution. The technical scheme is as follows: pulverized coal is fed into a reaction chamber of a gasifier and conducts a gasifying reaction under the effect of a gasifying agent at 1200-1650 DEG C to generate a crude synthesis gas; the crude synthesis gas is cooled by water mist sprayed out by an atomizing nozzle when rising above the reaction chamber; then, the crude synthesis gas rises, is fed into a fire tube boiler through a gas pipe with a membrane water wall and further cooled through heat exchange with water between a tube pass and a shell pass, and then is fed into a multi-tube cyclone dust collector and a fly-ash filter for further dust removal until the dust content is less than 1mg/m ; and after the dust removal, the crude synthesis gas enters an economizer again and is further cooled to 220-260 DEG C before entering the next process. The technology and system provided by the invention have the advantages of simple technology, wide coal adaptability, low equipment investment cost and operation cost and environmental friendliness.