The invention discloses a crystallizer bleed-out treatment method. Two-dimensional images of a slab are continuously collected during steelmaking and continuous casting at a preset time interval; the profile of a slab body is extracted from the current two-dimensional image of the slab by means of image segmentation, whether a foreign matter zone exists on the surface of the slab body or not in the current two-dimensional image of the slab is identified, and a first identification result is obtained; if the first identification result is yes, whether the foreign matter zone is increased from the current two-dimensional image of the slab to the next two-dimensional image of the slab or not is judged, and a first judging result is obtained; whether a surface temperature average value in the foreign matter zone is increased in a preset duration or not is determined, and whether the surface temperature average value is higher than a preselected temperature value or not is determined; and when the surface temperature average value is increased in the preset duration and higher than the preselected temperature value while the first judging result is yes, a pouring stop operation instruction is issued. According to the crystallizer bleed-out treatment method, the technical problem that bleed-out accidents cause great loss in the prior art is effectively solved, and the loss degree is further lowered.