The machining of titanium alloy Ti17 with WC/Co cemented carbide cutting tools under the traditional cutting and highpressure water jet assistance cutting methods was introduced, and a comparative analysis was made.Under the different cutting speeds and the water jet pressures, the evolution of tool wear and the changes of cutting forces and axial force were studied,the corresponding discussion was also carried out. The optimum water jet pressure and cutting speed were determined by experiments between cutting speed of 50~100 m/min and water jet pressure of 5~25 MPa. When the water jet pressure is 10 MPa，the best cutting speed is 8140 m/min.Compared to conventional lubrication,the tool life is increased by about 9 times and the efficiency is increased by about 30%.