Symptoms of formaldehyde poisoning are dominated by central nervous system, eye damage and metabolic acidosis. 1. Central nervous system: early drunkenness, blurred vision, insomnia, fatigue, dizziness and headache, and even blurred consciousness, coma, delirium, cerebral edema. 2. Eye damage: retinal congestion and hemorrhage, optic nerve atrophy, pale optic nerve papilla, etc. may occur. 3. Metabolic acidosis: the decrease of carbon dioxide binding capacity and thus the decrease of pH will lead to metabolic acidosis. Formaldehyde poisoning must be timely to the regular hospital treatment, under the guidance of a professional doctor to take appropriate measures, to avoid self-disposal delays in the condition, resulting in increased difficulty in treatment.