The hydraulic system of radiator fin cutting machine plays a leading role in the radiator fin production. Its performance directly affects the efficiency and quality of product line. The hydraulic system of cutting machine for radiator is composed of blanking circuit and support circuit. The hydraulic system realizes the cutting action using the reciprocating movement of the hydraulic cylinder. According to the requirement of equipment, the hydraulic drive system for the host was designed. Then the hydraulic system simulation model was built by the simulation software AMESim. Using the simulation model, the simulation analyses of the dynamic characteristics of the hydraulic system were completed. The hydraulic system has been through the debugging and put into production, running in good condition.