Abstract: An experiment has been made on the flow instability under station, inclination,fluctuation and rolling conditions in a 50 mm×2 mm parallel rectangular channel at the pressure of3MPa~8MPa. First of all, the effects of motion conditions on phenomena of flow oscillation have been studied in time domain and frequency domain. Then, by comparing the results under station condition, the effects of motion conditions on flow instability boundary were obtained. Finally, an empirical correlation of instability boundaries was correlated based on the experimental results.