The electro-hydraulic servo springs fatigue testing machine is the most popular equipment in springs fatigue test.The performance of the testing machine was mainly relied on the performance of hydraulic system and control system.Starting with the computation and design of hydraulic servo system,the models of the hydraulic system were built by using the method of transfer functions.A fuzzy controller based on genetic algorithm (GA) is designed for combining the fuzzy control and GA,which remedies deficiency of a kind of rough method that usually confirms the membership function according to experience.