The drugs used in patients with peritonitis are mainly for the correction of water-electrolyte disturbances, anti-inflammatory, and caloric and nutritional support. We use crystalloid and colloid fluids to correct water-electrolyte disturbances, plasma and albumin for severe cases, concentrated red blood cells for patients with significant anemia, hormones for more severe cases to reduce the symptoms of toxicity, and sodium bicarbonate for patients with combined acidosis. Patients with unstable blood pressure and increased pulse rate can also apply contracting or dilating agents depending on the situation, while the antibiotics selected are currently recommended to be treated with broad-spectrum, single antibacterial drugs, which may have better effects. When caloric supplementation is insufficient, the triad of inputting glucose, fatty milk, and amino acids is generally chosen to supply energy, while albumin should also be supplemented, and patients who are unable to eat for a long time should be given parenteral nutrition.