The present invention provides a method for treating and preventing scuticociliatosis in breeding fishes. Adding stabilized chlorine dioxide or chlorite, organic carboxylic acid and hydrogen peroxide into a cistern which is closed over ultraviolet, and make the concentration of them be above 0.5ppm and below 10ppm, above 0.015ppm and below 0.3ppm, above 5ppm and below 30ppm separately, and to implement drug bath to fish in the cistern. By means of the three medicament combination, it is easy to treat scuticociliatosis in breeding fishes. In addition, due to killing the shield infusorian, thusto prevent scuticociliatosis from occurring without blight to fishes.
