Abstract: Through model test of TGP's floodreleasing deep outlet,the characteristics of pressure distribution and cavitation are compared among different types of parabolic profile,and a chute type is put forward.The research results indicate that,in comparison with the parabolic type,the chute type's pressure and cavitation characteristics are evidently improved.The chute type is cavitationfree,but the parabolic type is difficult to avoid cavitation.The chute scheme doesn't induce any negative influences to the discharge capacity and characteristics of pressure and cavitation in the outlet'spressure section.Therefore , the chute type is a feasible type for the open channel under high velocity flow.