The invention discloses a cleaning device for a chemical stirring barrel. The cleaning device comprises a mixing barrel, the top of the stirring barrel is provided with a barrel cover, a positioning block is welded to the middle position of the top of the barrel cover, a movable cylinder movably sleeves the top of the positioning block, a movable rod movably sleeves the inner ring of the movable cylinder, a baffle plate is welded to one end, extending out of the bottom of the movable cylinder, of the movable rod, a fixing block movably sleeves the movable rod is welded to one end, extending into the mixing barrel, of the movable cylinder, circumferentially arranged connecting rods are hinged to the sidewall of the fixing block, and a first semicircular ring and a second semicircular ring which are symmetrically arranged and have a hollow structure are hinged to one ends, away from the fixing block, of the connecting rod. The device has the advantages of quickness in cleaning of the mixing barrel, remarkable cleaning effect, realization of cleaning of mixing barrels with different sizes by adjustment, convenience in cleaning, no need of replacing other cleaning devices, simplicity in operation, and convenience in use.