Tyrosinemia type I is an autosomal recessive disorder caused by the accumulation of tyrosine and its metabolites succinylacetone, 4-hydroxyphenyllactate and 4-hydroxyphenylpyruvate in the body due to a defect in the terminal enzyme of the tyrosine metabolism process, yohosyl acetoacetate hydrolase, which causes damage to the body. Tyrosinemia mainly accumulates in the liver and kidneys and can be life-threatening in severe cases. Effective treatment is available along with dietary therapy. However, because nitisinone may cause increased plasma tyrosine levels, resulting in eye and skin lesions and even brain development, patients need to be treated with nitisinone in combination with a diet low in tyrosine and phenylalanine. The recommended total protein intake for children <2 years of age is usually 3 g/kg-day, decreasing to 2 g/kg-day with age, with natural protein intake limited to 2 g/kg-day in infancy and reduced to 1 g/kg-day in childhood, and the rest of the protein provided by tyrosine- and phenylalanine-free powdered formula. In addition, a certain amount of vitamins and minerals should be given, and the plasma tyrosine concentration should be monitored regularly to adjust the dietary regimen when appropriate.