The invention discloses a circulation cooling pipeline of a three-level power module of an integrated gate commutated thyristor; a plurality of radiator circulation cooling pipelines are formed by connecting a capillary hose with a water-supply header, a backwater header and a square water-cooling radiator; and the capillary hose is further connected with the water-supply header, the backwater header, a water-cooling reactor of the three-level power module of the integrated gate commutated thyristor and a water-cooling resistor to form a plurality of impedance circulation cooling pipelines. The circulating water flows through the square water-cooling radiator, water-cooling resistor and water-cooling reactor in a power module unit so as to cool a main power heating power electronic devicein the power module, the radiating efficiency is greatly improved, thereby effectively protecting the power electronic device and guaranteeing the normal operation of a system; and the water circulating pipeline is simple in structure, material-saving and easy to replace.