<p>In order to study the influence of different axis ratios on the flow field characteristics around an elliptical cylinder. This paper is based on the finite element method, the drag coefficients, lift coefficients and flow field variation of elliptical cylinders with different axis ratios at low Reynolds number (Re = 200) are studied by solving the two-dimensional unsteady incompressible Navier–Stokes equations, Shannon entropy is used to reflect the change of flow field. According to the simulated results, the Karman vortex shedding frequency first decreases and then increases with the decrease of the axis ratios. As the axis ratios decreases, the mean drag coefficients keeps increasing, and the peak average velocity in the sampling area shows a gradually increasing trend. As the axis ratios keeps decreasing, the Shannon entropy shows obvious fluctuations, indicating that the reduction of the axis ratios enhances the instability of the flow field. The research results provide reference for the study of flow field characteristics of elliptical cylinder with different axis ratios.</p>