An integrated purification device and method for dust and acidic gas in a gas extraction pipeline comprises: a
cyclone-type primary
dust collector, comprising a lower box, a conical cylinder, a primary
dust collector air inlet duct, a cylinder, and a primary
dust collector exhaust duct; a dust removal and explosion-proof integrated self-excited dust collector, comprising a
liquid storage tank, a secondary dust collector air inlet duct, a secondary dust collector exhaust duct, a guide plate, and an explosion-proof
throttle plate; a dust exhaust box; an induced draft fan; and a direct digital controller. The present invention can effectively remove dust and acidic, toxic, and harmful gases in the extracted gas, prevent
corrosion of dust deposition pipelines and extraction pipelines, effectively avoid the transmission of explosions, and promptly depressurize the pipelines during explosions to avoid harm to surrounding workers.