The running quality of the wind tunnel power shaft system has a decisive influence on the efficiency and performance. With increase of the runtime of the shafting

rotor parts have inevitable mass eccentricity

which obviously strengthens the coupling function of torsional and bending vibration. In this paper

the subject investigated is power shaft system of one wind tunnel

on the basis of the established coupling formula

dynamic response of the shaft system is investigated by the difference method and new mark integral method

and then the subject which is simulated multi-supporting distributed mass model is analyzed in the two typical operating conditions of the harmonic attenuation urge and the asynchronous juxtaposition urge. The results can be reference to the qualitative analysis and quantitative study to the bending character of a complex power shaft system coupling vibration for one wind tunnel.