Abstract: With the development of superconducting technology,large-scale helium cryogenic system has been more used in large-scale frontier science engineering to keep the stable operation of superconducting equipment.Because of the pulsed heat load generated during the operation of superconducting equipment,the stable operation of cryogenic system is more demanding.In this paper,a general process of large-scale helium cryogenic system is introduced.The characteristics of pulsed heat load generated in three different superconducting Tokamak devices are compared.The commissioning methods of the cryogenic system in superconducting Tokamak devices scoping with pulsed heat load are systematically analyzed,which can be applied to other similar cryogenic system.