There are special antidotes for nitrite poisoning, and for mild cases, no special treatment is needed after gastric lavage, catheterization and diuretic application, but for those who have been poisoned to a greater extent and for a longer period of time, they must be sent to the hospital in time. Firstly, give gastric lavage treatment, apply activated carbon adsorption enema or magnesium sulfate for diarrhea, and apply 1% methylene blue injection, which is a special antidote for nitrite poisoning. Secondly, observe the changes of heart rate, blood pressure, pulse rate, oxygen saturation and other indices of the patient, and also observe the color of the patient’s mucous membrane and whether cyanosis subsides. If the color of the patient’s skin mucous membrane cyanosis does not subside or there is severe cyanosis, the application of methylene blue injection can be repeated if necessary.