This paper focuses on the pressure coefficient distribution in simplified model of some realistic turbine blade internal cooling channel for obtaining the characteristic of outflow rate allocations influence on pressure coefficient distribution. This model has been amplified geometrically according to analogous theory. Experiments with five outflow rate allocations of these three outlets including outlet1, outlet2, and outlet3, have been performed based on inlet Reynold number from 27000~34000. The experimental results show that : (1). the pressure coefficient distribution in the first channel has not been influenced obviously by different outflow rate allocations, besides in the second and the third channel; (2). the pressure coefficient of this model will wholly decline when increasing outflow rate allocation of outlet2 and decreasing outflow rate allocation of outlet1 and outlet3; (3). the pressure coefficient of the third channel will be more higher than other situations and the declining trend of pressure coefficient will be more gently than others when the outflow rate allocation of outlet3 increases.