The invention relates to a gasification method of a carbon-containing solid raw material and a used reactor. The gasification method is characterized by comprising the following steps of: reacting the carbon-containing solid raw material with oxygen in a reactor unit so as to generate synthesis gas, wherein ash flows downwards into a slag pool at the lower end of a gasification reactor in the slag form under the action of gravity force; allowing high-temperature synthesis gas which entrains molten ash residues to rise to a chill zone in the gasification reactor, injecting steam or/and water into the chill zone by using chilling equipment and chilling the high-temperature synthesis gas so as to freeze the molten ash residues entrained in the high-temperature synthesis gas into solid dust; introducing the synthesis gas which entrains the chilled solid dust into a dust removing unit so as to remove dust entrained in the synthesis gas; and introducing the synthesis gas into a waste boiler unit and generating steam by using process waste heat of the synthesis gas. The reactor provided by the invention isolates a gasification furnace from the waste boiler unit through respective shell and the dust removing unit is arranged between the gasification furnace and the waste boiler unit. The equipment has low wear rate and can run for a long time.