The flexible impact force of water jet is the mechanics criterion of material breakage by water jet. The nozzle shape has a great influence on the impact pressure. Five different nozzles were designed in this paper, and the impacting tests were conducted based on the self-designed jet-impact test platform. PVDF piezoelectric film sensor and the high speed camera were used to record the experimental data. It's indicated that water jet beam from the circular nozzle presents the best strand integrity. The shock wave induced by impacting from the circular nozzle has a great influence on the diffusion form of the liquid. These features cause the highest central impact pressure of circular nozzle. The impact pressures of water jets from square, triangular and cross-shaped nozzles are much lower than that of circular nozzle. The water jet from elliptical nozzle is the most divergent and its impact pressure is the smallest consequently. The peak pressures from all shape nozzles present nonlinear relationships with the pump pressure, but the duration time of these peak pressures nearly keep constant with the pump pressure.