The split Hopkinson pressure bar test equipment was improved through adopting multi-measures.A number of dynamic compression tests and dynamic split tests were conducted with the improved apparatus for the Three Gorges granite under high strain rate.It is found that strain rate effect is obvious and dynamic compression failure of the test simples can be divided into three patterns;i.e.edge fall apart,core no damage and completely failure.The failure mechanism of the rock is discussed;and the effects of strain rate on dynamic elastic modulus and dynamic compression strength are analyzed.Finally,a dynamic failure criterion of rock based on the Hoek-Brown failure criterion is proposed.