The invention discloses a fire-jet head, a combustion can and the application of the combustion can for fuel treatment. The fire-jet head comprise a feed pipeline, a first pipeline and a second pipeline which are connected sequentially, and the diameters of the pipelines increase sequentially. The first pipeline and the second pipeline are provided with gas incoming through holes. The fire-jet head has the advantages that fuel can burn more completely, smoke is prevented, natural environment and personnel health of workers can be protected, and the service life of the fire-jet head can be prolonged significantly.