The hydrodynamic performances of a novel hydraulic shock generator are examined.The shock generator is designed to impose the strong power of waterhammer in mining industry.The experimental results show that the Waterhammer produced by the periodic fast switch of a flowing fluid has diferent features with that of a single closure observed by other researchers.In particular,the intensity of the waterhammer depends largely on the switch frequency due to the interaction of successive pressure waves.These flow transient phenomenrr a are theoretically proved by the simulation results based on the finite difference method of characteristics.