Abstract: In the case of the plug energy dissipater flow, the characteristic of turbulence is studied firstly, then 3-D RNG k-ε mathematical model and the calculation program are established and verified properly by the physical model test data Based on the computational results of mathematical model, the head loss of plug energy dissipater flow is analyzed and generalized, showing that the head loss coefficient reducs rapidly, then increases evidently and finally increases according to linearity relation, when the ratio of plug section length to plug section radius increases from small value.According to the same radius of pressure tunnel, the head loss coefficient is affected by a variety of plug section radius more than that of plug section length, which can give reference to the design of plug energy dissipater.