Protein is a causative factor as well as an aggravating factor in hepatic encephalopathy, so patients with hepatic encephalopathy should strictly limit their protein intake. After protein intake, amino acids will be produced during intestinal digestion, which will be changed into ammonia under the action of intestinal flora. Normal liver function can convert blood ammonia into urea for excretion, but excessive protein intake in liver dysfunction will lead to excessive blood ammonia, which will cause ammonia toxicity. Ammonia is toxic to the brain, increasing inhibitory neuron activity, decreasing excitatory neurotransmitters, imbalance of neurotransmitters in the brain, and interfering with the energy metabolism of brain cells, ultimately leading to disorders of the central nervous system, and inducing or aggravating hepatic encephalopathy. Limiting protein intake, reducing tissue protein breakdown, and reducing nitrogen load is one of the ways to prevent and control hepatic encephalopathy, and it is recommended that patients seek medical attention in a timely manner and follow the doctor’s instructions for treatment.