The secondary pull-down process is an important process for preparing flexible radiation-resistant glass. However, it is difficult to accurately obtain the drawing characteristics of glass using secondary pull-down process and quickly adjust the process parameters. In this paper, the finite element simulation of ANSYS Polyfolw software was combined with actual drawing process parameters to simulate the changes of thickness field, velocity field and temperature field. The influences of secondary pull-down process parameters on the width and thickness of flexible glass after forming were analyzed and verified. The results show that in heating zone, the necking phenomenon causes the edge thickness of formed glass to be larger than center thickness, and the edge velocity component of glass along tensile direction is significantly smaller than center velocity component. In cooling zone, the glass edge temperature is significantly higher than center temperature. It is found that the heating temperature is positively correlated with the thickness of formed glass, and negatively correlated with width. The traction speed is negatively correlated with the thickness and width of formed glass. The initial thickness of glass is positively correlated with the thickness of formed glass, but negatively correlated with width.