Abstract: Experiments of a real aspect water model were conducted to study the influence of process factors on the characteristic parameters of unstable fluid flow in a continuous thin slab casting mould by using a wave gauge and the particle trajectory visualization method. The results show that the characteristic parameters of fluid flow vary with a certain periodicity. With increasing casting speed, the average jet impinging position and the average circumfluence center descend and the average wave height increases; more-over, the variation ranges of the jet impinging position, the circumfluence center and the wave height increase, the variation period decreases and the fluid flow becomes more unsteady. With increasing immersion depth of the submerged entry nozzle (SEN), the average jet impinging position and the average circumfluence center descend and the average wave height decreases; in addition, the variation ranges of the jet impinging position, the circumfluence center and the wave height decrease, the variation period increases and the turbulent flow becomes gradually calmness. With increasing SEN outlet angle downwards, the average jet impinging position and the average circumfluence center descend and the average wave height decreases; for a larger SEN outlet angel, even though the characteristic fluid flow moving range is larger, the variation period is greater and the level fluctuation becomes relatively stable.